Mind you I am only saying the earliest known writer, it's likely that most Christian writings are lost to history. And technically we don't even know who wrote the Gospels with any certainty. Only Paul's 7 undisputed letters are universally accepted by secular scholarship as being genuinely authored by Paul, the authorship of the rest of the New Testament is disputed.
There has never been a manuscript of a Gospel with anyone other than the traditional author attributed. And they’ve always been cited by the traditional names - even in Islamic, Jewish or heretical writings.
The arguments made in favour of Paul’s authenticity largely come from internal textual cues - but is that really more persuasive?
I don’t mean to suggest too strongly one side of the Gospel authorship debate over the other, only that these issues mix objective facts with subjective interpretation in a way that makes it very difficult to outsource to scholarly consensus.
Bible scholar Dan McClellan is on youtube and does short videos rebutting popular youtube/tiktok videos that make claims that aren't historical. Dan has said that the four names were not assigned to the texts until the second half of the 2nd century, probably around 180CE or so. That leaves 80-100 years where the books were in circulation before the naming convention was established.
The subject of authorship comes up frequently so he has addressed it a few times, but here is a short (under 7 minute) video. It isn't just an assertion, he gives reasons why he makes these claims:
There’s a big difference between the gospels not being cited by name directly, and not having a name. For example, the Gospels often cite Isaiah without using his name - just lifting direct quotes.
And there’re allusions to apostolic naming in things like Justin Martyr’s first apology, Ch67 (155CE, dating largely from it being co-addressed to Marcus Aurelius):
“ the memoirs of the apostles or the writings of the prophets are read, as long as time permit”
"Data over dogma." Dr. Dan McClellen is an engaging source for historically accurate interpretations and understandings of the bible. I encourage others to check his content out.
I am only repeating what modern scholarship has determined, wikipedia does far more justice than I could. Church tradition is far more assertive in authorship claims.
