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] To speak quite plainly, it is one thing to forgive sins, and another thing to put them away or drive them out. The forgiveness of sins is obtained by faith, even though they are not entirely driven out; but to drive out sins is to exercise ourselves against them, and at last it is to die; for in death sin perishes utterly. But both the forgiveness and the driving out of sins are the work of baptism. Thus the Apostle writes to the Hebrews, [Heb. 12:1] who were baptised, and whose sins were forgiven, that they shall lay aside the sin which doth beset them. For so long as I believe that God is willing not to count my sins against me, my baptism is in force and my sins are forgiven, though they may still, in a great measure, remain. After that follows the driving out of my sins through sufferings, death, etc. This is what we confess in the article [of the Creed], "I believe in the Holy Ghost, the forgiveness of sins, etc." Here there is special reference to baptism, for in it the forgiveness takes place through God's covenant with us; therefore we must not doubt this forgiveness.