To forgive others as a Christian is to extend the same grace that we have already received from God in Christ. While Reformed traditions emphasize that our forgiveness of others is not a merit-earning work but a necessary fruit of the Spirit, they unanimously teach that one who has truly experienced God's pardon cannot persist in a heart of unforgiveness toward a neighbor.
Christian forgiveness is not a human invention; it is a response to the vertical reconciliation already achieved by Christ. We are instructed to be 'kind one to another, tenderhearted, forgiving each other, even as God also in Christ forgave you' (Ephesians 4:32). Our ability to forgive is not a condition for earning God's favor, but the necessary expression of a heart that has been transformed by the gospel. As the Heidelberg Catechism Q. 56 teaches, we believe that God, for the sake of Christ's satisfaction, no longer remembers our sins against us, and it is from this overflow of undeserved grace that we are empowered to release others.
The parable of the unmerciful servant reminds us of the radical imbalance between our debt to God and our neighbor's debt to us (Matthew 18:32-35). When we harbor bitterness, we deny the reality of the grace we claim to possess. The Westminster Larger Catechism Q. 194 explains that we are emboldened to pray for and expect forgiveness from God when we have the 'testimony in ourselves' that we forgive others from the heart. While we do not 'merit' God's mercy by our own forgiving, our refusal to forgive serves as a solemn warning that a heart closed to the neighbor is a heart that has not truly grasped the magnitude of its own debt that God has cancelled in Christ.