What does this mean? Are we are forgiven only as we forgive?
Interestingly this is the only part of the prayer that Jesus feels compelled to amplify upon.
For if you forgive other people when they sin against you, your heavenly Father will also forgive you. But if you do not forgive others their sins, your Father will not forgive your sins.
We know that the gospel is a free gift - nothing that we could have earned on our own. So this can not mean we have to demonstrate to God how good we are at forgiving other people before he will forgive us.
Jesus is simply describing the very nature of created order - we must give in order to receive. For example, I cannot receive love if I do not give love. Augustine said, “God gives where He finds empty hands”
If our hearts are such that we can only see how others have hurt and offended us, we cannot see how we have offended God and so we find no need to seek forgiveness. If we are always calculating how much this person or that person has violated our rights then we will not, by the very nature of things, be able to pray this prayer.
Forgiveness is the only thing that breaks the cycle of retribution and releases the grace of heaven among human beings. Karl Barth said, “To clasp the hands in prayer is the beginning of an uprising against the disorder of the world.” When we get before God and come to grips with the pain and the tension and the angst of our fallen world and the sinful nature of our own hearts, when we to clasp our hands before our heavenly Father and ask Him to bring it all back into alignment, this is truly the beginning of an uprising!