“For this reason the kingdom of heaven may be compared to a king who wished to settle accounts with his slaves.” (Matthew 18:23)
The words “FOR THIS REASON” are key to the meaning of this passaage. Jesus had just told Peter in :22 that he was not to forgive his brother merely the magnanimously suggested “seven times” (instead of the traditional three), “but up to seventy times seven.” WHY is it that we are to be so lavish in our forgiveness of others? “For this reason …”.
It was at this point that Jesus began to tell the parable of the two debtors: the slave who was forgiven an amount he could have never repaid, but who in turn would not forgive his fellow slave for a relatively minor amount. His reluctance to forgive his brother, when he himself had been forgiven so much, was indefensible, and brought rebuke and punishment from his master.
The lesson, of course, is that we have been forgiven so much by the Lord: a lifetime of sins of deed, word, and thought; commission and omssion — all forgiven completely and graciously by God through Jesus Christ. Having experienced such grace, there is now no excuse for us not to forgive anyone, for anything that they might have done to offend us. If we are not willing to forgive their relatively insignificant debt (compared to all we have been forgiven by God) then it shows just how little we really understand the grace of God, and what He has done for us. In fact, when a person is unwilling to forgive others, it seriously calls into question whether they have ever really been forgiven by the Lord. Those who realize they have been graciously forgiven such a great debt — every sin they have ever committed — must surely be quick to forgive anyone’s transgressions against them.
“For this reason” Jesus says, you MUST forgive. Yes … even THAT person.