Forgiveness is not ignoring the sin committed by the offender. God does not overlook sin; man must not either. Jesus says that we must rebuke, not ignore (Luke 17: 3). Nor is putting the offender under test, while we spend talking about his offense and saying that we will forgive if he changes and passes his period proves.
We can know what forgiveness is when we observe what God does when he forgives ... God clears our offenses (Acts 3:19). God does not keep record of our offenses that He has forgiven. When He forgives He says: "Blot and new account!", God forgets our offenses and draws them out of his memory (Hebrews 8:12), God treats us in the same way that He treated us before sinning, and receives us with open arms (Luke 15: 20-24).
Remember that God is always willing to forgive us, with forgiveness there is healing, harmony and obedience to God.