. It says that baptism must be in the name of the Trinity.
That’s not, on a literal basis, that is to say, according to the actual words in Matthew 28:19, correct. What it literally says, since the word Trinity is a theological term of art coined by Tertullian in the third century, is that baptism must be in the name of the Father, the Son and the Holy Spirit, or Holy Ghost, or the equivalent, I mean, obviously, in different languages, the words are different, but the meaning is the same, and I don’t know of any church that teaches that the baptism must be done in a specific language in order to be efficacious.
For reference, in the King James Version, which I rather like but do not regard as uniquely authoritative, Matthew 28:19 reads as follows:
“Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: [20] Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.”
The Gospel of Matthew contains the authoritative instruction on the matter (since the longer ending of Mark is of uncertain authenticity, we cannot regard it as being a source of dogmatic instruction), that takes priority over the narratives in Acts, particularly when one considers that if you baptize in the name of the Father, Son and the Holy Ghost, you have baptized in the name of Jesus Christ, effectively, whereas the reverse is not true, in that baptizing in the name of each person of the Trinity is inclusive of God the Son, whereas baptizing in the name of God the Son is not inclusive of the other persons of the Trinity.
This is relevant because every Christian denomination I am familiar with baptizes in the name of the Father, Son and Holy Ghost, even the Baptists and Adventists, and as such, it is an important point of commonality; the only people who I am aware of who do not use this formula are Oneness Pentecostals, who are not Trinitarian but rather Modalist, and thus are not Nicene Christians (since obviously, they do not accept the Nicene Creed, which is Trinitarian rather than Modalist).