Since Christians live in this world, and in this world you need money to survive, the topic of what the Bible says about money is useful to look at to help us have a godly attitude toward money. The Bible does have lots to say about money, and actually it is not completely against having money or wealth. What does matter is your attitude toward God and money, as we will see. However, if you want to get right to the question "Why doesn't God make me rich?", you might be more interested in my article Why doesn't God help me win the lottery?.
Money is not Evil
First, it must be noted that there were godly, rich people in the Bible, such as Abraham, King David, Solomon, Job, as well as the wealthy women who supported Jesus (Luke 8:3). Some proverbs say that riches are a blessing from God (Prov. 10:22, 13:21). RG LeTourneau is one example of a Christian businessman who earned large amounts of money, but lived on only 10% of his income and gave away 90% to charity . To him, the question wasn't "how much of my money I give to God, but rather how much of God's money I keep for myself". The article  notes that:
"He believed that we are all stewards of God's money. In other words we are money managers for God. God's will is not for us to horde the money he gives us but to use it to God's good. If we are good money managers and we tithe, and help others, than God will give us more money to manage. LeTourneau figuratively illustrated his generosity as a man with a shovel. All LeTourneau did was shovel money to charities, churches and organizations that needed help. He always had plenty to give because God was shoveling money to him with an even bigger shovel."
So while there are some examples of God blessing people with much wealth so that they can be a blessing to others, this is more of an encouragement to wisely manage what you have been given, and then leave it up to God if he desires to bless you with more. For example, promising that you'll give some percent of your money to charity does not guarantee that God will help you win the lottery. But God is pleased when you manage responsibly whatever financial resources he has given you and do your best to be generous to others.
However, while being rich might mean someone is blessed by God, it might also mean that one is corrupt and selfish and has been exploiting others. For example, rich pastors of mega-churches in the USA may appear to be blessed by God, but it could be that they are actually selfish, greedy, and have been exploiting their congregations with the "prosperity gospel", which claims that if their parishioners give "sacrificially", then God will bless the parishioners with more money. So poor grandmothers living on welfare and pensions give their last cent to the pastor, denying themselves medicine or food, while the pastor has multiple mansions and fancy cars, private jets, and other excessive luxuries. This is not right, and these pastors (if they are actually Christians) will have to account to Jesus for their horribly selfish spending and the manipulation of their congregations.
The Love of Money is the Root of Evil
The popular quote "money is the root of all evil" is actually wrong. The verse is "the love of money is the root of all evil" (1 Timothy 6:10). So as noted above, just because someone is rich does not mean they are evil. But what really matters is where a person's heart is. If someone loves money or the things money can buy more than they love God, then that is idolatry. Jesus warns that people cannot serve both God and money (Luke 16:13). The "love of money" is listed with other sins such as being a drunkard, violent, and argumentative which disqualify someone from being a church leader (1 Timothy 3:3). One sign of the end-times approaching is that people will be lovers of money, along with numerous others sins (2 Timothy 3:1-5).
It is interesting that many "rich" countries in the world today are those with a historically Christian majority, perhaps due to the Christian strong work ethic and the types of governments we have put in place, which allow for economic mobility and growth. Yet there are negatives to capitalism, such as how it is driven by greed and selfishness, how it encourages unsustainable use of resources, and has led to significant wealth imbalances. James 5:1-6 could be seen as a criticism against greedy multinational corporations which pay excessively low wages to workers and reap billions of dollars in profit:
"You rich people should cry and weep! Terrible things are going to happen to you. Your treasures have already rotted, and moths have eaten your clothes. Your money has rusted, and the rust will be evidence against you, as it burns your body like fire. Yet you keep on storing up wealth in these last days. You refused to pay the people who worked in your fields, and now their unpaid wages are shouting out against you. The Lord All-Powerful has surely heard the cries of the workers who harvested your crops. While here on earth, you have thought only of filling your own stomachs and having a good time. But now you are like fat cattle on their way to be butchered. You have condemned and murdered innocent people, who couldn't even fight back." (James 5:1-6, CEV).
For example, Walmart makes billions of dollars in profit each year, but Walmart workers receive government welfare in order to have a minimum standard of living ,. Companies that use workers in developing countries to make products often pay them pennies per day and abuse them because the workers are not protected by western labour standards ,.
If you examine the Old Testament laws regarding the Sabbath year and Jubilee years (e.g. Deut 15:1-11, Leviticus 25:8-22), these laws periodically "reset" the Israelite economy, providing forgiveness of debts, land redistribution, and release of slaves. It is possible that God designed these laws to prevent the rich from becoming so rich that eventually they would own everything and everyone else would be in perpetual slavery. There are other numerous laws to protect the poor and those who have no land (Deut 24:19-22). I believe that this shows that God is concerned to prevent unjust wealth distribution, which easily leads to the rich abusing and exploiting the poor. However, the Israelites rarely followed these laws, and the prophets regularly criticized them for this (e.g. Isaiah 5:8; Ezekiel 22:29; Micah 2:1-3; Habakkuk 2:5-6).
So while money is not evil, and being rich is not evil, it seems money and the desire for more of it can certainly lead people to do evil things. These verses show God cares about the poor, and hates systems or people who encourage economic inequality and injustice. As Christians, we should do what we can to encourage companies to pay a living wage to their workers and to protect the human rights of those working in developing countries who make the things we buy.
Warnings in the Bible Against Loving Money
There are many verses which show that loving money more than God can be spiritually dangerous. Paul writes "People who want to be rich fall into all sorts of temptations and traps. They are caught by foolish and harmful desires that drag them down and destroy them. The love of money causes all kinds of trouble. Some people want money so much that they have given up their faith and caused themselves a lot of pain."(1 Timothy 6:9-10, CEV). Jesus warns that some people who hear the gospel might fall away when they become distracted with pursuing riches (Mark 4:19, Luke 8:14).
There are examples of rich people who missed out on heaven. A rich man ignored the suffering of the poor beggar Lazarus, but when the rich man died he ended up in hell where all of his wealth did not do him any good (Luke 16:19-30). Another rich man wanted to follow Jesus, but he was too attached to his money and could not give it up even for Jesus (Matthew 19:16-23). So some people prefer their money over Jesus, perhaps because they fear losing it and the security or luxury it can buy. However, our money only helps us for this lifetime, and no one knows how long they will live. We don't want to be foolish like the man in Luke 12:13-21. Here is the story:
"A rich man's farm produced a big crop, and he said to himself, 'What can I do? I don't have a place large enough to store everything.' Later, he said, 'Now I know what I'll do. I'll tear down my barns and build bigger ones, where I can store all my grain and other goods. Then I'll say to myself, 'You have stored up enough good things to last for years to come. Live it up! Eat, drink, and enjoy yourself.'' But God said to him, 'You fool! Tonight you will die. Then who will get what you have stored up?' This is what happens to people who store up everything for themselves, but are poor in the sight of God." (Luke 12:13-21)
So while having money might make you feel secure, it does not guarantee your life will be safe.
Heaven is Better than Having Worldly Wealth
Therefore, it's much better to put your trust in Jesus, since even if you die soon, or lose all your money and become poor, or never get a chance to become as successful as you want, it will not matter. No matter how rich or poor we are in this life, Christians can be happy that because of what Jesus did for us on the cross, we will have eternal life forever, in a new immortal body (1 Cor. 15:42-55), in the New Jerusalem where every tear will be wiped away (Rev 21:4), on a restored Earth which will be beyond compare with our present suffering (Rom. 8:18). There is no amount of money which can buy this, and nothing we can do to ever earn this - it can be received only in faith by placing our trust in Jesus. Heaven is going to be better than anyone has ever imagined (1 Corinthians 2:9)! We are promised a place to live in heaven (John 14:2), and it will be better than any mansion that any architect has ever built on earth. The New Jerusalem (Revelation 21:11-24) will be a glorious city which God has personally designed (Hebrews 11:10) where we will live in the very presence of God!
In comparison with eternity in heaven, the tiny sliver of time we have on this planet is nothing, and so we should live with heaven in mind. Having a heaven-focused mindset helps the rich avoid trusting in their riches for security, encourages them to be responsible with what they have been given by God, and encourages them to be generous to others. Also, if you are poor, having a heaven-focused mindset will help you learn to be patient and satisfied with what you have, and you can have faith that even though you won't have everything you want in this life, heaven will be beyond compare. So you don't need to spend time or money trying to achieve luxuries in this life, and can be satisfied with a simpler life for now.
Also, on earth all things are subject to decay, destruction, or being stolen, which is why Jesus says "Don't store up treasures on earth! Moths and rust can destroy them, and thieves can break in and steal them. Instead, store up your treasures in heaven, where moths and rust cannot destroy them, and thieves cannot break in and steal them" (Matthew 6:19-20, CEV). If I spend my time and abilities serving God, using the resources I have been given wisely, and developing the sort of character that makes me a good servant, then God will reward that in heaven (Matthew 25:14-30). It is better to spend my time serving God and possibly earning heavenly rewards (1 Corinthians 3:10-15) which will last forever, will never get broken or wear out, will never get stolen or destroyed, and which will be better than anything I can buy in this life.
God Holds Us Accountable for How We Use Our Money
As mentioned briefly, there are several verses which suggest that Christians will be held accountable for how they spend their money, as we are just managing it for God temporarily. Jesus says "Anyone who can be trusted in little matters can also be trusted in important matters. But anyone who is dishonest in little matters will be dishonest in important matters. If you cannot be trusted with this wicked wealth, who will trust you with true wealth? And if you cannot be trusted with what belongs to someone else, who will give you something that will be your own?"(Luke 16:10-12). This means if we cannot be responsible for the money God gives us in this life, which is not really ours, then how can he expect us to be responsible with what he might entrust to us in heaven?
There is a parable about some servants in Luke 19:11-26, and a slight variant of it in Matthew 25:14-30. Each servant is given a different amount of money from their master, and is told to invest it wisely to make a profit for when their master returns. The servants who put their money to work and earned more were rewarded by their master. In the version in Luke, the servants are rewarded by being made rulers of multiple cities, in proportion to how well they invested their money. But the servant who hid their money out of fear is punished (by losing everything he had and by being thrown out into the outer darkness - often seen as another term for hell). So this parable shows that while we cannot control how much we are given by God (just as the servants did not have control over how much money they were given), they were held accountable for how responsible they were with what they had been given. Yet this idea applies not just our money, but everything we have been given from God - our time, our abilities, our opportunities, etc. So even if you don't have much money, maybe think about how God might want you to use your time or other abilities to serve him well. And rich people are not off the hook for how they use their time or abilities either, even if they are doing a good job at being responsible and generous with their money.
This idea is repeated in Luke 12:48 which says "If God has been generous with you, he will expect you to serve him well. But if he has been more than generous, he will expect you to serve him even better." (CEV). This idea can apply to how much money we are given, as those who are fortunate to have good jobs or live in wealthy countries are probably expected by God to be much more generous than those who make only barely enough to survive. But it also applies to our abilities, time, and other resources. If God hasn't given you much money, but has given you opportunities to share the gospel, or to spend time volunteering at a charity helping others, then you should take advantage of those, instead of spending your time on yourself sitting at home doing nothing. (Note: God doesn't expect us to serve him 24 hours a day. He knows we need time to sleep, eat, relax, and spend time with family. I don't believe God wants people to burn out, as then you are even less useful to God than if you had taken some breaks along the way to rest and be properly recharged).
Also, it should be noted that what matters is not the absolute amount that we give, but how much we give out of what we have. This is shown in the story about the poor widow in Mark 12:41-44. While others were donating large amounts of money to the temple, a poor widow comes and only puts in two pennies. But Jesus says "I tell you that this poor widow has put in more than all the others. Everyone else gave what they didn't need. But she is very poor and gave everything she had. Now she doesn't have a cent to live on."(Mark 12: 43-44, CEV). While we might question the widow's wisdom, what matters is her heart was in the right place, and she wanted to do what she could to support the priests and honour God with her money. So from this story we can learn that even if we are poor, being generous with even a few dollars is not ignored by God, and is actually counted as more impressive than rich people who donate thousands of excess dollars to charities.
A Proper Christian Attitude Toward Money
First, we should recognize that everything we have comes from God. God is the ultimate source of wealth, as he owns everything in the universe (Psalm 50:9-11). Even our ability to work and provide for ourselves comes from God: "When you become successful, don't say, 'I'm rich, and I've earned it all myself.' Instead, remember that the Lord your God gives you the strength to make a living" (Deut. 8:17-18). So we should thank God that we have a place to live, food to eat, clothes to wear, good health to be productive, and a job to pay for everything we need. Try to be grateful for what you have been given and appreciate the good things in your life now, instead of being envious of what others have, which will make you bitter.
So if God owns everything in the universe, then one might wonder then why God doesn't make all Christians rich. It seems that the mistaken idea that religion should make people rich was around even as far back as the early church. Paul says "These people think religion is supposed to make you rich. And religion does make your life rich, by making you content with what you have. We didn't bring anything into this world, and we won't take anything with us when we leave. So we should be satisfied just to have food and clothes."(1 Timothy 6:5-10, CEV). So just because you're a Christian is no guarantee that God will make you rich. Even rich people are never satisfied with what they have and always want more (Ecclesiastes 5:10). But in general, God will not allow his children to starve or be financially destitute (Proverbs 10:3), and so I believe God will provide for our basic needs. This might be done by God giving you the ability to work and earn money, by giving you a job, by providing for you through others' charity or through government programs.
Therefore, perhaps the best advice is "Keep your life free from love of money, and be content with what you have" (Hebrews 13:5, CEV). Be grateful for God's blessings and provision for your needs, and praise him if you are able to afford a few nice things, and enjoy them. Also try to be responsible with what financial resources God has given you, and also be generous to others. Remember Paul's advice: "Warn the rich people of this world not to be proud or to trust in wealth that is easily lost. Tell them to have faith in God, who is rich and blesses us with everything we need to enjoy life. Instruct them to do as many good deeds as they can and to help everyone. Remind the rich to be generous and share what they have. This will lay a solid foundation for the future, so that they will know what true life is like."(1 Timothy 6:17-19, CEV).
This has been a lot to read. It seems the Bible says more about money than one might first expect. While money itself is neutral and can be used for good or evil, it is the love of money that the Bible is concerned about, as well as the injustice around how the poor are mistreated by the rich. We must keep our priorities straight and love God more than money, and remember that we are going to be accountable to God for how we use our money. It helps to remember that this life is only a tiny sliver of time compared to all eternity, and so do not get too attached to worldly money or things, as heaven will be far better than anything you can buy here. Money doesn't make our lives secure, as anyone might die anytime, and if one dies without having placed their trust in Jesus then they will spend eternity in hell. Therefore, faith in Jesus is worth more than any amount of money in the world. Christians are expected to be generous and responsible with our money. When we come face to face with Jesus, we want to hear him say: "You are a good and faithful servant. I left you in charge of only a little, but now I will put you in charge of much more. Come and share in my happiness!"(Matthew 25:21, CEV).
 www.themillionaireblog.com "God's shovel is bigger than mine!"
 Americans for Tax Fairness "Walmart on Tax Day: How Taxpayers Subsidize America's Biggest Employer and Richest Family"
 Slate.com "Are Walmart's Prices So Low Because It's Employees are on Food Stamps?" by Krissy Clark
 Cambridge Times: "Bangladesh factory that sews garments for The Gap and Old Navy accused of abusing workers" by Raveena Aulakh, Oct. 4, 2013.
 Institute for Global Labour and Human Rights