Well, I stand corrected. I’d always assumed (and had said as much on the BHT recently) that a valid baptism required use of the trinitarian formula (“in the name of the Father and of the Son and of the Holy Spirit”), in contrast to baptism in the name of Jesus only.
Luther, however, gives this pretty short shrift in his 1520 work, On the Babylonian Captivity of the Church (page references are to the linked edition), in which he attacks “that idle dispute about the ‘form’ of baptism” and writes:
The Greeks say: “May the servant of Christ be baptized,” while the Latins say: “I baptize.” Others again, adhering rigidly to their pedantry, condemn the use of the words, “I baptize you in the name of Jesus Christ,” although it is certain the apostles used this formula in baptizing, as we read in the Acts of the Apostles (2:38; 10:48; 19:5). (p.185)
So Luther rejects as a “vain” contention, lacking any scriptural proof, the argument that a valid baptism must use the form: “I baptize you in the name of the Father, and of the Son, and of the Holy Spirit”.
What’s particularly interesting is Luther’s reason for taking this position. It is because baptism is not a human act, but rather it is Christ himself who baptizes us. Hence what matters is that it is truly Christ that is acting in our baptism, not what the precise words used are. As Luther writes:
For man baptizes, and yet does not baptize. He baptizes in that he performs the work of immersing the person to be baptized; he does not baptize, because in so doing he acts not on his own authority but in God’s stead.
Hence we ought to receive baptism at human hands just as if Christ himself, indeed, God himself, were baptizing us with his own hands. For it is not man’s baptism, but Christ’s and God’s baptism, which we receive by the hand of a man, just as everything else that we have through the hand of somebody else is God’s alone. (p.184)
The point is that we baptize “in the name of” the Father, the Son and the Holy Spirit, not in our own name. And Luther is emphatic that this is not simply a case of saying that there is an outward aspect of baptism which is done by human hands, and an inward aspect which is done by God. Rather:
Ascribe both to God alone, and look upon the person administering it as simply the vicarious instrument of God, by which the Lord sitting in heaven thrusts you under the water with his own hands, and promises you forgiveness of your sins, speaking to you upon earth with a human voice by the mouth of his minister. (p.184)
It strikes me as equivalent to the legal position in which the acts of a duly-authorised agent are regarded as the acts of the agent’s principal.
So what matters in baptism is that it is clearly seen to be done in the name of the Triune God, even if the Trinitarian formula itself is not used. If someone has been baptized with the words, “I baptize you in the name of Jesus Christ”, then that baptism is still truly the act of the Trinitarian God, and so they have truly been baptized in the name of (that is, by the human minister as agent for) the Father and the Son and the Holy Spirit.
As Luther writes:
Baptism truly saves in whatever way it is administered, if only it is administered not in the name of man, but in the name of the Lord. (p.186)
I’d be interested to know what other people think about this, and indeed whether Luther later stepped back from this quite radical (though also persuasive) position. Also, does this have any impact on the Lutheran insistence on the ipsissima verba in the Lord’s Supper?