Our lives are the sequence of mistakes. Everyone wants to give and take love with friends, but unfortunately we make a lot of mistakes throughout our lives. When we make a mistake or experience failure, what we need is not self-discouragement but self-confidence. If we repent our faults and make them as a good chance to improve ourselves, these faults would not be harmful but profitable for both you and your friend.
For instance, we sometimes used to be rude to our best friends, which finally breaks friendship with them by incurring their grudge. It would be a really serious fault in our lives. What will you do in this case? You may suffer from the conscience on your serious guilty, or may continue to justify your bad behaviour. However, such an attitude never solve this situation. The first step is to pray to the God with sincere repentance. Then stand up promptly and go to your friend to make a sincere apology to him. It is very simple but not easy because it requires your modesty and strong confidence.
Nevertheless, your friend might not forgive you for a long time. In that case, never hurry up to be reconciled with him, and never give up your gesture for peace with him even though he never look up your face. You should be patient. At any time, he will finally return back to you if you do not give up to recover your friendship.