XII. Here, then, is the place to discuss the third thing in the sacrament, i. e., faith, to wit, that a man should firmly believe all this; viz., that this sacrament not only signifies death and the resurrection at the Last Day, by which man is made new for an everlasting, sinless life; but also that it assuredly begins and effects this, and unites us with God, so that we have the will to slay sin, even till the time of our death, and to fight against it; on the other hand, that it is His will to be merciful to us, to deal graciously with us, and not to judge us with severity, because we are not sinless in this life until purified through death. Thus you understand how a man becomes in baptism guiltless, pure and sinless, and yet continues full of evil inclinations, that he is called pure only because he has begun to be pure, and has a sign and covenant of this purity, and is always to become more pure. Because of this God will not count against him the impurity which still cleaves to him, and, therefore, he is pure rather through the gracious imputation of God than through anything in his own nature; as the Prophet says in Psalm xxxii, "Blessed is he whose transgression is forgiven; blessed is the man unto whom the Lord imputeth not iniquity." [Ps. 52:1 f.]
This faith is of all things the most necessary, for it is the ground of all comfort. He who has not this faith must despair in his sins. For the sin which remains after baptism makes it impossible for any good works to be pure before God. For this reason we must hold boldly and fearlessly to our baptism, and hold it up against all sins and terrors of conscience, and humbly say, "I know full well that I have not a single work which is pure, but I am baptised, and through my baptism God, Who cannot lie, has bound Himself in a covenant with me, not to count my sin against me, but to slay it and blot it out."
XIII. So, then, we understand that the innocence which is ours by baptism is so called simply and solely because of the mercy of God, which has begun this work in us, bears patiently with sin, and regards us as though we were sinless, This also explains why Christians are called in the Scriptures the children of mercy, a people of grace, and men of God's good-will. [Eph. 5:1, 9] It is because in baptism they have begun to become pure, [Luke 2:14] and by God's mercy are not condemned with their sins that still remain, until, through death and at the Last Day, they become wholly pure, as the sign of baptism shows.
Therefore they greatly err who think that through baptism they have become wholly pure. They go about in their unwisdom, and do not slay their sin; they will not admit that it is sin; they persist in it, and so they make their baptism of no effect; they remain entangled in certain outward works, and meanwhile pride, hatred, and other evils of their nature are disregarded and grow worse and worse. Nay, not so! Sin and evil inclination must be recognized as truly sin; that it does not harm us is to be ascribed to the grace of God, Who will not count it against us if only we strive against it in many trials, works, and sufferings, and slay it at last in death. To them who do this not, God will not forgive their sins, because they do not live according to their baptism and covenant, and hinder the work which God and their baptism have begun.
[Sidenote: Baptism and Repentance]
XIV. Of this sort are they also who think to blot out and put away their sin by "satisfaction," [7] and even regard their baptism lightly, as though they had no more need of it after they had been baptised,[8] and do not know that it is in force all through life, even until death, nay, even at the Last Day, as was said above.[9] For this cause they think to find some other way of blotting out sin, viz., their own works; and so they make, for themselves and for all others, evil, terrified, uncertain consciences, and despair in the hour of death; and they know not how they stand with God, thinking that by sin they have lost their baptism and that it profits them no more.
Guard yourself, by all means, against this error. For, as has been said, if any one has fallen into sin, he should the more remember his baptism, and how God has there made a covenant with him to forgive all his sins, if only he has the will to fight against them, even until death. Upon this truth, upon this alliance with God, a man must joyfully dare to rely, and then baptism goes again into operation and effect, his heart becomes again peaceful and glad, not in his own work or "satisfaction," but in God's mercy, promised him in baptism, and to be held fast forever. This faith a man must hold so firmly that he would cling to it even though all creatures and all sins attacked him, since he who lets himself be forced away from it makes God a liar in His covenant, the sacrament of baptism.
[Sidenote: Baptism and Penance]
XV. It is this faith that the devil most attacks. If he overthrows it, he has won the battle. For the sacrament of penance also (of which we have already spoken)[10] has its foundation in this sacrament, since sins are forgiven only to those who are baptised, i. e., to those whose sins God has promised to forgive. The sacrament of penance thus renews and points out again the sacrament of baptism, as though the priest, in the absolution, were to say, "Lo, God hath now forgiven thee thy sin, as He long since hath promised thee in baptism, and as He hath now commanded me, by the power of the keys,[11] and now thou comest again into that which thy baptism does and is. Believe, and thou hast it; doubt, and thou art lost." So we find that through sin baptism is, indeed, hindered in its work, i. e., in the forgiveness and the slaying of sin; yet only by unbelief in its operation is baptism brought to naught. Faith, in turn, removes the hindrance to the operation of baptism. So much depends on faith.
[Sidenote: Forgiveness and Sanctification]