Human relationships tend to return like-for-like.  When people love you, you love them; and those who hate you are hated in return.  Using the analogy of family clothes or uniform, Paul says that our outward appearance should be like that of God. He is patient, very patient. He does not get angry quickly.  That does not mean that God is never angry, but that He withholds His judgement, waiting for sinners to come to repentance (2 Peter 3:9).  When they do, He is forgiving, completely forgiving.

The church is full of people who have a track record of sinful thoughts, untrue and unkind words, and ungodly behaviour.  Although everyone who has received Jesus is a child of God, and therefore our brother or sister, nobody is yet perfect.  Even the Apostle Paul admitted that he still struggled (Romans 7:15-25).  It is hardly surprising that we struggle with the imperfections of others, and they sometimes have a hard job to keep loving us.  That is why we need to be well practised in ‘bearing with one another’.  The Greek word means to ‘endure’, ‘suffer’, ‘continue unbowed’.  That takes much grace from the Lord particularly with those who are slow at becoming like Christ.  So we may have to forgive them many times (Matthew 18:21-22).
 
Love is not a feeling; it is an action of self-giving.  Christ gave Himself for the world but only those who believe and repent will receive His love.  He gave Himself even for those who reject Him.  He is patient and is waiting for them to repent so that they can receive His love. In the same way, we may need to wait a long time for some people to repent, but that is what we long for - not that they will be condemned (Romans 2:4).
 
That sort of love holds the Christian together, and holds whole fellowships together.  As 1 Corinthians 13:4-7 says, "Love is patient, love is kind. It does not envy, it does not boast, it is not proud.  It does not dishonour others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs.  Love does not delight in evil but rejoices with the truth.  It always protects, always trusts, always hopes, always perseveres."  That is the 'family uniform' of heaven.  It is our responsibility to put it on and wear it every day.