I have a Greek New Testament here, given to me when I was in college.
This book gives the Greek text according to very modern scholarship (Nestle-Aland text 26th edition), and underneath the text gives ALL variant readings and the different manuscripts you can find them in.
The readings in the Greek are rated from A to D - basically A means “absolutely sure” and D means “dicey”, though they don’t stand for that.
If there are no alternative readings, that particular text is given an A rating. If there’s a lot of doubt it is given a D rating. In one passage we studied at college it was completely uncertain whether Jesus crossed over to the land of the Gerasenes, Gadarenes or Gergasenes so that had a D rating. (Can’t remember any others, it was a few years ago).
Of course, textual criticism isn’t a totally exact science and scholars can’t say that the current text is perfect, but since this Greek Testament gives ALL the alternatives we can see most of it with certainty, most of the rest with near certainty, and a tiny fraction with less certainty - but all the options are given.
What one of the articles says about dating of the manuscripts is true in part - but very bad history and very bad scholarship, twisting evidence to prove a point. For more information on that see this link, in the section on matter and form of the Sacrament.
newadvent.org/cathen/02258b.htm
The article would have us believe that this trinitarian formular is a really late corruption. But there it is in Tertullian, Justin Martyr and others. This article on baptism is long, sometimes a little complex - but it is fantastic.
Anyway, that’s the background. Let’s get on to Matthew 28:19.
There are NO alternative readings given for manuscripts for this verse.
To give you an idea of how exact the testament is, it has a variant reading for verse 20. Some manuscripts add the word “amen” on the end. The testament lists all the early and important manuscripts that do and don’t include “amen”.
There, that’s the textual viewpoint - ALL manuscripts give a trinitarian formula in Mt28:19. There has not been a forgery.
However, the first of the articles linked to points out that in the book of Acts people baptised “in the name of Jesus”. I’m not sure of an answer as to why, but here’s a grammatical attempt, covering the verses the article refers to.
In Mt28:19 the call is to baptise IN (Greek - EIS) the name…
In Acts 2:38 people are baptised IN (Greek - EPI) the name…
This is something different. Basically grammatically to be baptised IN (EIS) the name of is to be baptised
by the authority of. To be baptised IN (EPI) is to be baptised
for him and his service.
These are entirely different things, and the second doesn’t mean that a trinitarian formula baptising by trinitarian authority wouldn’t have been used. The people being baptised were all Jews. They were baptised for Jesus - which wouldn’t exactly have been approved of by the religious leaders - and this is the point that Luke brings out in this verse.
Acts 10:48 has another word for IN - the Greek is EN. Here the emphasis is on public profession of faith and belief in Christ as saviour and sovereign. Again this does not rule out the trinitarian formular being used for baptism - but stresses something else important to Catholics.
Acts 22:16 quoted by that article makes no mention of baptismal formulas, just says we should be baptised and tells us to call on the name of the Lord. Which we do during the course of any catholic baptismal service.
1Cor1:12-15 makes no mention of baptismal formulae except to say that we should avoid baptising in the name of Paul (or whoever) or thinking of ourselves baptised in that name.
1Co6:11 - again no mention of baptismal formula.
Rom6:3 and Gal3:27 are quoted too which use the word “eis” - we were baptised EIS (into) Jesus Christ. But this again has nothing to do with baptismal formulae, and every Catholic would agree that we were baptised into Christ (see for example CCC1227)
Now, in Acts 8:16, and Acts 19:5 we see people baptised “in the name of the Lord Jesus”. The Greek word here for IN is EIS. These two verses prove the biggest problems to me in unravelling the meaning and grammar. For both say baptised in (eis) the name of the Lord Jesus.
However, in Acts19:15 the baptism in Jesus’ name seems to be not a formula, per se, but a contrast to the baptism of John. In Acts8 they have been baptised in the name of Jesus - but have not received the Holy Spirit so there must be something awry. I think I need to think a bit more about that one.
Actually the newadvent link I’ve posted says a lot about this, including the history, grammar and everything else. But I only thought of the article a moment ago so some of what I’ve typed will be duplicated there.
My apologies that this answer is so long. I was just going to put in the textual evidence but then clicked on the dimensions of truth link and got carried away. That website is run by a man who sounds very interesting - read the story about his death & resurrection and see what you think.
Anyway, I hope some of what I’ve typed will be useful. Or failing that that the newadvent site will be useful.