“So my heavenly Father will also do to every one of you, if you do not forgive your brother or sister from your heart.” There’s an unbreakable bond between God's forgiveness and the forgiveness we are to offer one another, making it illogical and impossible for us to accept the mercy of the Lord and then refuse to extend mercy to others. Jesus summarizes this quite succinctly in his teaching of the Lord’s Prayer, “Forgive us our trespassers, as we also have forgiven those who trespass against us.”
Forgive us our trespassers — that’s what we ask of God.
As we have forgiven those who trespass — that’s what we offer our neighbors.
In the divine economy of the kingdom of heaven, you can’t have one without the other.
Our Lord is a merciful God who is willing to do the dirty work of blotting out our transgressions, washing us from our iniquity, and cleansing us from our sin. That’s a job that would overwhelm anyone. But God is betting that we have been transformed by his forgiveness into the kind of people who can do the hard work of forgiving others. God knows that his mercy can have a surprising and wonderful effect — it can create a community of merciful people.
God is willing to do the most disgusting of dirty jobs — the removal of our sin through his gift of forgiveness. All he asks is that we turn and do the same for others. Seven times. Seventy-seven times. Maybe even 490 times.