The location of these two verses on forgiveness supports the conclusion that verse 13 was a later insertion in the Lord’s Prayer. These two verses continue the theme of verse 11 (compare Matt. 6:12). Without the intervening line of praise to God, these two verses closely match their apparent context and expand verse 11.
The forgiveness of trespasses flows directly out of the forgiveness of debts. We owe other human beings debts, but our trespasses comprise our debt to God. This passage repeats the principle that our horizontal relationships are the model by which God conducts our vertical relationship. This approach, however, raises a question. If God judges according to divine and eternal justice, how can he justly judge us according to our human judgments? Shouldn’t God judge us against some eternal truth rather than our actions?
The answer to this question lies in understanding the purpose of mortality. Unfortunately, that understanding is often limited. For instance, we say that God is testing us. That concept helps clarify the nature of our moral agency, but it is ultimately unsatisfying. Why should God test us if he already knows the answers? If God is omniscient, should he not already know what we will do before we do it? If so, doesn’t the very definition of God preclude his gaining any information from the testing?
If the testing cannot be for proving ourselves to God (since by definition he already knows), then the testing and proving must be for us. How are we tested and tried? Psalm 66:10 suggests: “For thou, O God, hast proved us: thou hast tried us, as silver is tried.” In the Revised English Version this is translated: “For you, God, have put us to the test and refined us like silver.” The New International Version has: “For you, O God, tested us; you refined us like silver.” Such “trying” does not test to see if it is silver. The “trying” of the silver refers to the refining process, not the identification. When “tried,” impurities contained in the silver are burned out in the furnaces. In human terms, mortality is the furnace that proves the silver within us. We are children of God, “and if children, then heirs; heirs of God, and joint-heirs with Christ” (Rom. 8:17).
The true silver is already in us, but it needs to be refined. Agency is the process by which we exercise our incipient God-like natures against opposition so that we develop God’s attributes. We are to continue this process of refining our spiritual qualities until we have become “perfect, even as [our] Father which is in heaven is perfect” (Matt. 5:48).