Most Christians have heard the phrase "Love your enemies.". But what does this actually mean in day to day life? How does God expect us to treat others that dislike us or even hate us? The Bible has a lot of insight on this topic, and it may be useful to Christians to examine this subject in detail, so that we know how to put it into practice.
As an introduction, there are 3 things we are called to do as Christians towards our enemies. First, we must love them, and so we will examine what this means, and how that love is supposed to be shown. Secondly, we should not take revenge on them, and third we should learn to forgive them. Let's look at each of these topics here.
We Should Love Others
Most Christians know that we are supposed to love God and love others: "Love the Lord your God with all your heart, soul, and mind. This is the first and most important commandment. The second most important commandment is like this one. And it is, 'Love others as much as you love yourself.'"(Matthew 22:37-39). And we should also treat others the same way we want to be treated (Matthew 7:12). Jesus did not specify who these "others" were that we should love and treat like we would want to be treated. Therefore, they apply to everyone - even people we don't like or don't get along with, or even people who outright hate us.
Now, the question is what does "love" actually mean? Does it mean we have to like them? Does it mean we have to want to spend time with them and enjoy being around them? I don't believe so. In the Greek language, there are several words that are translated into "love" in the Bible . There is "agape", which means an unconditional, intelligent, "benevolent love expecting nothing in return" . This is different from "phileo" which is more like friendship, affection, and love between spouses. Then there is "eros", which is usually physical, passionate love like when people are first dating. Source  states that in the Bible, whenever it talks about God loving us, it is always "agape" love.
There is a definition of "agape" love in 1 Corinthians 13:4-8: "Love is kind and patient, never jealous, boastful, proud, or rude. Love isn't selfish or quick tempered. It doesn't keep a record of wrongs that others do. Love rejoices in the truth, but not in evil. Love is always supportive, loyal, hopeful, and trusting. Love never fails."
This is the same sort of love we are supposed to have for all people. It doesn't mean we must be best friends with everyone we meet, or even enjoy being around them. It means that when we interact with people, we should be kind, patient, not proud or stuck up, not bossy or pushy, not snarky, don't give the "cold shoulder". We should genuinely try to care about the well-being of the person we are speaking to.
A good test example of agape love can be found in the story of the Good Samaritan in Luke 10:25-37. A stranger is walking by and notices an injured man on the side of the road. The stranger approaches and helps the man, gives him first aid, and then takes him to an inn for further care. The stranger pays all of the man's expenses, and never expects to be paid back, or even get any recognition for his good deed. You can test if you have agape love by applying this to anyone you know. Would you be able to help them if they were in genuine need, and not expect anything in return? If no, then perhaps you need to work on developing your agape love.
It is important to note that no person can ever love perfectly. We only have so much love that we can humanly give on our own, and eventually we will run out. However, if we have accepted Jesus and have the Holy Spirit living in us, then we have an unlimited reservoir of love that can only come from God. If you have a hard time loving others, pray that God will give you the love you need. You can't do it on your own - only through God's strength can we love those who are truly difficult to love.
We Should Love Our Enemies
This type of agape love that we discussed above is the same sort of love we should have for our enemies. Jesus said: "I tell you to love your enemies and pray for anyone who mistreats you."(Matthew 5:44). Again, this does not mean that we will want to spend time with people who dislike us or who are mean to us. But it means that we should not be mean or unkind around them - we shouldn't bad-mouth them or spread rumours about them. We shouldn't hope that bad things happen to them. And, if they genuinely needed help then we should do all we can to help them. Even if you think they may need help, then go offer it. If they refuse then don't try to force it on them, but you can at least offer.
Jesus also says we should pray for our enemies. We can pray that they may change their minds and be kinder to us, and we should always pray that they will come to know Jesus. God wants everyone to be saved (1 Timothy 2:4), even our enemies. If we are kind to our enemies, we are providing a very strong witness to them of what Jesus is like, and they might think it's strange enough to take note and wonder why you don't hate them also. This can be the starting point of introducing them to Jesus.
Yet even if our enemies are determined to hate us, no matter how kind we are to them, there is comfort to be found in the Bible. Jesus said "But love your enemies and be good to them. Lend without expecting to be paid back. Then you will get a great reward, and you will be the true children of God in heaven. He is good even to people who are unthankful and cruel."(Luke 6:35-36). Also, "God will bless you when people insult you, mistreat you, and tell all kinds of evil lies about you because of me. Be happy and excited! You will have a great reward in heaven."(Matthew 4:11-12) So, we are commanded to help our enemies, and we are promised a reward by Jesus if we are mistreated for being a Christian.
Additionally, being kind to someone who genuinely hates you will drive them crazy: "If your enemies are hungry, give them something to eat. And if they are thirsty, give them something to drink. This will be the same as piling burning coals on their heads."(Romans 12:20). The "burning coals" may be the frustration they experience from not getting the response they want from you. Being served and treated nicely by a person you hate must be infuriating. Ironically, being kind is how you can "get back" at someone you dislike, without doing anything wrong.
And finally, we are commanded to try to live at peace with everyone (Romans 12:18). The NIV version of this verse says "If it is possible, as far as it depends on you, live at peace with everyone.". Some people may not want to live at peace with us, yet as much as possible we should not try to cause problems or confrontations (without compromising our Christian standards or faith). If someone genuinely hates you, then try to avoid them if possible, and don't get into fights on purpose. Don't pursue them and try to actively "love" them if they do not want to be loved - just wish them well, and be prepared to deal kindly with them and/or help them if they ever need it in the future.
Don't take Revenge on Your Enemies
If someone has done something wrong to you, the most natural reaction is to want revenge. We think we will feel better by making them suffer like we have suffered, or sometimes even worse than we have suffered. However, as Christians we must resist this attitude. The Bible says several things about not taking revenge on others: "Don't mistreat someone who has mistreated you."(Romans 12:17-18), and "Dear friends, don't try to get even. Let God take revenge. In the Scriptures the Lord says, 'I am the one to take revenge and pay them back.'"(Romans 12:19). We should take comfort in knowing that God will be the one to take revenge on our enemies, because He can do it far better than we can. God might not take revenge on them in this life, but that means they will probably get something more serious in the afterlife.
Jesus said, "But I tell you not to try to get even with a person who has done something to you. When someone slaps your right cheek, turn and let that person slap your other cheek. If someone sues you for your shirt, give up your coat as well. If a soldier forces you to carry his pack one mile, carry it two miles. When people ask you for something, give it to them. When they want to borrow money, lend it to them."(Matthew 5:39-42). This doesn't mean to be a pushover - it means that by demonstrating that you will not take revenge, and by sacrificing more than they have asked of you, they will stop and wonder why you're doing it.
For example, in Roman times the soldiers would often grab bystanders to carry their packs. By willingly carrying it for further than demanded, the soldier would really start to wonder "What's wrong with this guy?", and may be prompted to ask about it. This is an excellent opportunity to say something like "Well, I'm a Christian, and we're supposed to love others the same way that Jesus loves us. So I thought I'd do a little extra to help you out and show you that love in a real way.". They may think you're crazy, but you've done your job and you'll get a reward for it in heaven. And this act may be one of many that eventually convinces them to follow Jesus.
We Should Forgive Our Enemies
So even if we can be kind to our enemies, and avoid taking revenge on them, there is one more thing we must do towards our enemies, and that is to forgive them. In fact, we are supposed to forgive others the same way that God has forgiven our sins. If we refuse to forgive others, perhaps it is an indication that we are not truly saved: "If you forgive others for the wrongs they do to you, your Father in heaven will forgive you. But if you don't forgive others, your Father will not forgive your sins."(Matthew 6:14-15). And also: "Don't condemn others, and God won't condemn you. God will be as hard on you as you are on others! He will treat you exactly as you treat them."(Matthew 7:1-2).
There is the story that Jesus told in Matthew 18:21-35 of an official who owed a king fifty million silver coins. The king ordered the official, his wife, kids, and all his possessions to be sold to pay the debt. The official begged for mercy, and the king felt sorry and forgave all of the debt that was owed. But later, the official sees another man that owed the official a small amount of money. Instead of being kind and forgiving the debt, just as the king had done to the official, the official had the other man arrested and thrown in jail. The king found out about this, and was not pleased. He arrested the official and threw him in jail until he could pay back the original debt to the king. At the end, Jesus said "That is how my Father in heaven will treat you, if you don't forgive each of my followers with all your heart. So since we have been forgiven by God of all our sins, we must forgive others when they sin against us.
Forgiving is different than forgetting, however. When we forgive someone, we may still remember what they did, but we will not feel angry or have burning resentment or hate in our hearts towards them. An example of how forgiveness works is: "you reach into the unchangeable past and cut away the wrong from the person who wronged you; you erase the hurt in the archives of your heart". The topic of forgiveness and how to do it takes much more analysis and time than we have here, and even the most devout Christian may still have a hard time doing it in reality. You can pray and ask God to help you learn how to forgive, and read other inspirational stories such as about Corrie Ten Boom - a survivor of a German concentration camp who later met and forgave one of the guards who previously worked there . She said "Forgiveness is not an emotion; it is an act of the will.", and so when confronted with the guard, she willed herself to put out her hand to shake his hand, and when she did then the Holy Spirit filled her with the love and forgiveness towards him that she did not have in herself.
Forgiveness is not just for the one who offended us - it helps ourselves as well. It's not healthy to contain rage and anger towards anything for a long period of time. By forgiving, we can finally let go of all of that hate and anger and be at peace. There is no point dragging around all these hurt feelings and hate towards others if we can forgive and be free of it.
So as we have seen, the Bible has lots of information on how God expects us to treat our enemies. When we are called to "love our enemies", it does not mean being best friends with them - it means that we are to treat them kindly and to help them if they ever genuinely need it. Also, we must not take revenge on them - trust that God will take any revenge for us on our behalf, and His revenge will be better than any we can do. Then, we must forgive them - since we have been forgiven by God how can we dare to not forgive others.If we can do these three things towards our enemies, perhaps they will wonder why we aren't responding like a "normal" person would. It might give us opportunities to tell them about Jesus, and we will be rewarded in heaven for being mistreated by others if they hate us for being Christians. It's not easy, but this is what God expects of us, and so we should try our best to follow what the Bible teaches about how to act towards our enemies.
References www.albatrus.org - What is Love?
 www.ChristianityToday.com - The Scandal of Forgiveness
 PnP On the Road - On Forgiveness