From the Reformer
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.
For to be baptized in the name of God is to be baptized not by men, but by God Himself. Therefore although it is performed by human hands, it is nevertheless truly God’s own work. From this fact every one may himself readily infer that it is a far higher work than any work performed by a man or a saint. For what work greater than the work of God can we do?
—Martin Luther, Large Catechism
Pulling It Together
Why do I need to be baptized. What does that “work” do for me? These are the wrong questions. These questions are better: What does the Lord command? What is it that God wishes to do for me? Be sure of this at least: the Church has been baptizing believers since its earliest days. She has done so because of the admonition of scripture and the example of her Lord.
If you would have the Lord say that he is “well pleased” with you, obey.