We have now finished the three chief parts of the common Christian doctrine. Besides these we have yet to speak of our two Sacraments instituted by Christ, of which also every Christian ought to have at least an ordinary, brief instruction, because without them there can be no Christian; although, alas! hitherto no instruction concerning them has been given. But, in the first place, we take up Baptism, by which we are first received into the Christian Church. However, in order that it may be readily understood we will treat of it in an orderly manner, and keep only to that which it is necessary for us to know. For how it is to be maintained and defended against heretics and sects we will commend to the learned. In the first place, we must above all things know well the words upon which Baptism is founded, and to which everything refers that is to be said on the subject, namely, where the Lord Christ speaks in the last chapter of Matthew, v. 19: Go ye therefore and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost. Likewise in St. Mark, the last chapter, v. 16: He that believeth and is baptized shall be saved; but he that believeth not shall be damned . In these words you must note, in the first place, that here stand God's commandment and institution, lest we doubt that Baptism is divine, not devised nor invented by men. For as truly as I can say, No man has spun the Ten Commandments, the Creed, and the Lord's Prayer out of his head, but they are revealed and given by God Himself, so also I can boast that Baptism is no human trifle, but instituted by God Himself, moreover, that it is most solemnly and strictly commanded that we must be baptized or we cannot be saved, lest any one regard it as a trifling matter, like putting on a new red coat. For it is of the greatest importance that we esteem Baptism excellent, glorious, and exalted, for which we contend and fight chiefly, because the world is now so full of sects clamoring that Baptism is an external thing, and that external things are of no benefit. But let it be ever so much an external thing here stand God's Word and command which institute, establish, and confirm Baptism. But what God institutes and commands cannot be a vain, but must be a most precious thing, though in appearance it were of less value than a straw. If hitherto people could consider it a great thing when the Pope with his letters and bulls dispensed indulgences and confirmed altars and churches, solely because of the letters and seals, we ought to esteem Baptism much more highly and more precious, because God has commanded it, and, besides, it is performed in His name. For these are the words, Go ye baptize; however, not in your name, but in the name of God.