(Tr. vii. 16.) For no excuse will abide you in the day of judgment, when you will be judged by your own sentence, and as you have dealt towards others, will be dealt with yourself.
Then, as I said before, meaning to signify, that of all things He most loathes and hates bearing malice, and most of all accepts the virtue which is opposite to that vice; He hath after the prayer also again put us in mind of this same point of goodness; both by the punishment set, and by the reward appointed, urging the hearer to obey this command.
"For if ye forgive men," saith He, "your heavenly Father will also forgive you. But if ye forgive not, neither will He forgive you."
With this view He hath again mentioned heaven also, and their Father; to abash the hearer by this topic likewise; that he of all people, being of such a Father, should be made a wild beast of; and summoned as he is to heaven, should cherish an earthly and ordinary sort of mind. Since not by grace only, you see, ought we to become His children, but also by our works. And nothing makes us so like God, as being ready to forgive the wicked and wrong-doers; even as indeed He had taught before, when He spake of His "making the sun to shine on the evil and on the good."
For this same cause again in every one of the clauses He commands us to make our prayers common, saying, "Our Father," and "Thy will be done in earth as it is in heaven," and "Give us the bread, and forgive us our debts," and "lead us not into temptation," and "deliver us;" everywhere commanding us to use this plural word, that we may not retain so much as a vestige of anger against our neighbor.
How great punishment then must they deserve, who after all this, so far from themselves forgiving, do even entreat God for vengeance on their enemies, and diametrically as it were transgress this law; and this while He is doing and contriving all, to hinder our being at variance one with another? For since love is the root of all that is good, He removing from all sides whatever mars it, brings us together, and cements us to each other. For there is not, there is not one, be he father, or mother, or friend, or what you will, who so loved us as the God who created us.
But if that which is written, I said, Ye are gods, but ye shall die like men, (Ps. 83:6, 7.) is said to those who for their sins deserve to become men instead of gods, then they to whom sins are forgiven are rightly called men.
(Serm. in Mont. ii. 11.) Here we should not overlook that of all the petitions enjoined by the Lord, He judged that most worthy of further enforcement, which relates to forgiveness of sins, in which He would have us merciful; which is the only means of escaping misery.
(Enchir. 74.) Whoever does not forgive him that in true sorrow seeks forgiveness, let him not suppose that his sins are by any means forgiven of the Lord.
And certainly we should not heedlessly neglect to call attention to the fact that of all the pronouncements in which the Lord has ordered us to pray, he has deliberately attached a very special commendation to the pronouncement that deals with the forgiving of sins. In this pronouncement he wished us to be merciful because that is the only prescribed means of avoiding miseries. Indeed, in no other petition do we pray in such a manner as to make a kind of covenant with the Lord, for we say, "Forgive us as we also forgive." If we default in this covenant, the whole petition is fruitless, for he says, "For if you forgive men their trespasses, your heavenly Father also will forgive you; but if you do not forgive men their trespasses, neither will your Father forgive your trespasses."
By the word Amen, He shows that without doubt the Lord will bestow all things that are rightly asked, and by those that do not fail in observing the annexed condition, For if ye forgive men their sins, your heavenly Father will also forgive you your sins.
This condition is also necessary, because without it there is no remission of sins; hence: But if you will not forgive, etc. Nor is this surprising, because no sin can ever be forgiven without charity: "Charity covers all offenses" (Pr 10:12). For he who harbors hatred toward anyone is not in charity, and therefore his sin is not forgiven: "Man harbors anger against man" (Sir 28:3); "Judgment without mercy" (Jas 2:13).
But someone might believe that since the offense must be forgiven, the Church sins when it does not forgive. It must be said that if the offender seeks pardon, one would sin by not forgiving. But if he does not seek pardon, then one either does not forgive on account of hatred, and so sins; or on account of the good of that person or of others, so that evil may not become habitual, and so does not sin.
This is also connected with the foregoing. Thine is the kingdom has reference to Thy kingdom come, that none should therefore say, God has no kingdom on earth. The power, answers to Thy will be done, as in earth so in heaven, that none should say thereon that God cannot perform whatever He would. And the glory, answers to all that follows, in which God's glory is shown forth.
He does not say that God will first forgive us, and that we should after forgive our debtors. For God knows how treacherous the heart of man is, and that though they should have received forgiveness themselves, yet they do not forgive their debtors; therefore He instructs us first to forgive, and we shall be forgiven after.
I find 'Forgive us our sins as we forgive those that sin against us.' There is no slightest suggestion that we are offered forgiveness on any other terms. It is made perfectly clear that if we do not forgive we shall not be forgiven. There are no two ways about it. What are we to do?
It is going to be hard enough, anyway, but I think there are two things we can do to make it easier. When you start mathematics you do not begin with the calculus; you begin with simple addition. In the same way, if we really want (but all depends on really wanting) to learn how to forgive, perhaps we had better start with something easier than the Gestapo. One might start with forgiving one's husband or wife, or parents or children, or the nearest N.C.O., for something they have done or said in the last week. That will probably keep us busy for the moment.
Source: Mere Christianity, Book 3, Chapter 7: Forgiveness