The man who knows he has been forgiven, only in and through the shed blood of Christ, is a man who must forgive others. He cannot help himself. If we really know Christ as our Saviour our hearts are broken and cannot be hard, and we cannot refuse forgiveness. If you are refusing forgiveness to anybody I suggest that you have never been forgiven.
– Martyn Lloyd-Jones, Studies in the Sermon on the Mount, pp. 348-9.