It is very interesting that the apostles asked Jesus to increase their faith after He spoke of forgiveness. They observed all of the wonderful miracles Jesus performed and that never inspired them to ask for greater faith. 

Walking in love and forgiveness with each other takes as much faith as any miracle we will ever believe for.

The basis of forgiveness is the love and mercy of God. It is only because God first loved and forgave us that we can love and forgive others. If we aren't walking in the forgiveness of God, we won't minister it to others. 

He forgave us before we repented or asked for forgiveness.

The bible tells us to forgive as Christ has forgiven us. God offered His forgiveness towards us while we were yet sinners. Forgiveness was offered to all unconditionally. But only those who receive the offered forgiveness through repentance and faith are received as sons of God.

We are to forgive others their trespasses, just as God has forgiven us our trespasses. We forgive whether or not the other person repents or wants our forgiveness. 

But we cannot restore such a person to complete relationship until there is repentance on his part. Failure to distinguish between forgiveness and restoration with their different conditions, has caused some people to make themselves vulnerable to unscrupulous people and suffer tragic results. 

Complete restoration is dependent on repentance. We must walk in forgiveness!