Christianity is not just a set of instructions of "Do not do these things....", it actually goes further and encourages us to "do this" after the "Do not do this"
Our new life in Christ does not just stop us from doing what is bad or sinful, however it also encourages us to do now what is right in God's sight.
"But love your enemies, do good, and lend, hoping for nothing in return; and your reward will be great, and you will be sons of the Most High. For He is kind to the unthankful and evil." Luke 6:35 (NKJV)
We have to do what God has said in the verse above, and if we have had a real change in our life, we will do it with great delight and happiness, for it is not easy to love your enemies, only a real change can make this happen.
God is not asking us not to just not to hate our enemies and just try to keep away from them, rather He wants us to love them, which means that we need to help them, take care of them and do everything we can to a person we love.
Why does God want us to do this? What's wrong in going the way of the world and hate our enemies and try to repay them evil for evil?
To hate others and repay with evil is the devil's way, for in doing so, he is able to destroy both persons and destine them for hell, however with God's way we are trying all the possibility to win our enemy to become good by seeing our behaviour, by seeing our patience, dependence & trust upon the Lord and who knows seeing all this, he too may shed off his/her hatred from their heart and with a repentant heart try to befriend us and thus in doing so, we would surely have won one brother or sister for Christ and thereafter live at great peace and solace.
There is no greater peace and comfort than which comes from forgiveness, when you really forgive and forget the wrong done to you, not only do you bless others, you also do good to yourself and thus please God.
Christianity is a blessed path, it is a comforting nature, it is just loving others as Christ loves us.