While the divine institution and Word of God in baptism are of prime importance, the office of faith must also be made prominent. Faith is the third element in baptism. Faith does not make the sacrament; but faith appropriates and applies to self what the sacrament offers. Non sacramentum, sed fides sacramenti justificat. Nor are we left in doubt as to what is here meant by the term "faith." In paragraph fourteen it is explicitly described. Faith, we are then taught, is nothing else than to look away from self to the mercy of God, as He offers it in the word of His grace, whereof baptism is the seal to every child baptised. Luther's purpose, in this discussion, being to guard against the Mediæval theory of any opus operatum[12] efficacy in the sacrament, he would have wandered from his subject, if he had entered at this place into any extended discussion of the nature of the faith that is required. A few years later (1528), the Anabaptist reaction, which over-emphasised the subjective, and depreciated the objective side of the sacraments, necessitated a much fuller treatment of the peculiar office of faith with respect to baptism. To complete the discussion, the citation of a few sentences from his treatise, Von der Wiedertaufe, may, therefore, not be without use. Insisting that, important as faith is, the divine Word, and not faith, is the basis of baptism, he shows how one who regards faith, on the part of the candidate for baptism, essential to its validity, can never, if consistent, administer baptism; since there is no case in which he can have absolute certainty that faith is present. Or if one should have doubts as to the validity of his baptism in infancy, because he has no evidence that he then believed, and, for this reason, should ask to be baptised in adult years, then if Satan should again trouble him as to whether, even when baptised the second time, he really had faith, he would have to be baptised a third, and a fourth time, and so on ad infinitum, as long as such doubts recurred.[13] "For it often happens that one who thinks that he has faith, has none whatever, and that one who thinks that he has no faith but only doubts, actually believes. We are not told: 'He who knows that he believes,' or 'If you know that you believe,' but: 'He that believeth shall be saved.' [14] In other words, it is not faith in our faith that is asked, but faith in the Word and institution of God. Again: "Tell me: Which is the greater, the Word of God or faith? Is not the Word of God the greater? For the Word does not depend upon faith, but it is faith that is dependent on God's Word. Faith wavers and changes; but the Word of God abides forever."[15] "The man who bases his baptism on his faith, is not only uncertain, but he is a godless and hypocritical Christian; for he puts his trust in what is not his own, viz., in a gift which God has given him, and not alone in the Word of God; just as another builds upon his strength,