This passage
has given rise to the question whether St. Ambrose taught, as some
others certainly did (probably on his authority), that baptism in the
Name of Christ alone, without mention of the other Persons, is
valid. But it is difficult to believe that St. Ambrose meant more
than to refer to the passage in the Acts as implying Christian
baptism. He says just below that baptism is not complete unless
one confess the Father, Son, and Holy Spirit, which would seem to imply
the full formula, and he would hardly dissent from St. Basil, who
distinctly asserts [De Sp. Sanct. XII.] that baptism without
mention of the Three Persons is invalid; and St. Augustine [De
Bapt. lib. vi. c. xxv. 47] says that it is more easy to find
heretics who reject baptism altogether, than such as omit the right
form. Compare also St. Ambrose on St. Luke vi. 67; De
Mysteriis, IV. 20; De Sacramentis, II. 5 and 7, especially
the latter when he says: In uno nomine…hoc est in nomine
Patris et Filii, et Spiritus Sancti.