"I forgave you your entire debt because you begged me to. Should you not have had pity on your fellow servant, as I had pity on you?" The parable Jesus tells today is the story of a king, but in truth it is about Jesus himself. He is the "king" who has forgiven our debts. We are the "servants" whose sins have earned us chastisement. But when we repent and ask for Christ's mercy, he grants it to us without hesitation.
The point of the parable, then, is that we too should extend this mercy to others. We should not be like that "wicked servant" who begged for mercy but would not show it to others. Elsewhere, Jesus teaches us to pray, "Forgive us our debts as we forgive our debtors" (Mt. 6:12). We use different words, but a similar meaning when we pray the Our Father asking God to "forgive us our trespasses as we forgive those who trespass against us." But are we sure that we mean what we say?
It's important to pause and evaluate how we are doing in this regard. Are we harboring any grudges? Are there people we refuse to forgive? Is there a situation where we are seeking revenge instead of extending mercy? Jesus asks us to do otherwise. He reminds us that we have already been forgiven. We are right now enjoying the benefits of his forgiveness. So we are called to bear in mind our own sins, failings, weaknesses, and "debts" when we deal with others instead of thinking that we are perfectly innocent and acting as if we've never been the beneficiary of mercy. So let us do our best to forgive as we have been forgiven. This doesn't mean approving of wrong behavior; God doesn't ask us to do that. But he does ask us to let go of bitterness and foster mercy instead.