The bible encouraged us to forgive those who might have offended us. The bible fid not specifically say ee should forgive and forget but it encouraged forgiveness. We must forgive those who have offended us regarding the magnitude of the sin and by doing so, we shall be highly rewarded by lord.
Forgiveness means the sending away of anger and hatred but not meaning forgetting the wrong. It is easy to forgive but I don't think it is easy to forget because one’s you sight the person, who offended you before but has been forgiven by you, you start remembering his or her actions towards you, so it is not easy to forget a sin.
It is advisable to forgive others because if we sin against God and adk him for forgiveness of sin he would forgive us, so why should one not forgive another. In Colossians 3:13, it says “Bear with each other and forgive whatever grievances you may have against one another. Forgive as the lord forgive you”. So the above scripture tells us to forgive as God whatever sins the person may have committed.
In excess, we should forgive and forget and let go of malice, bitterness, grudges and hatred of one another and speak the gospel to each other so that we can enter the kingdom of God.