But again, “another Jesus” didn’t factor into these verses. This sounds like a “No true Scotsman” argument. “No one who knows the real Jesus wouldn’t agree with me!”II Corinthians 11:4. It's a warning. Those with "eyes to see" will get it - the reason (and he SAYS so!) that Paul GAVE that warning was because, and I quote in modern English, "I'm afraid [when this happens] that you just might put up with it."
There are many people - IMHO - who don't recognize a 'fake jesus' from the Real Messiah, Whose 'job description' is right in the literal meaning of His real Name - the "Salvation of Yah" - Yahushua.
If He was not "sinless" - He was a fake.
If He violated Deuternomy 13, he was a fake, and even, by His own Word, deserving of death.
If He taught against His own Instruction about marriage, as just one example relevant here, He was a fake.
But He - the Real One - did not.
And - IMHO again - the reason He gave us SO much information, so many 'proof texts' through His "torah and prophets" (as He referenced in that verse you don't like, Matthew 5:17-19) about His Character, and thus 'name' and very Identity, was so there would be no doubt about the real versus the fake.
"Because false christs" WILL arise and deceive NOT just many, but, "if possible, even the elect." (Matthew 24:24)
He said so!
“Not everyone who says to Me, ‘Lord, Lord,’ shall enter the kingdom of heaven, but he who does the will of My Father in heaven..."
What, even if they say 'the Prayer'? Could there possibly be something more?
"Many will say to Me in that day, ‘Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?’"
Hmm. "in your name." Wouldn't that be enough? What is He getting at here? Does He really expect (for example) them to have the ability to discern between Him and an imposter? (The demons, even, in Act 19:15 seemed to have a clue.)
“And then I will declare to them, ‘I never knew you; depart from Me, you who practice lawlessness!’ (Matthew 7:21-23)
Interesting. Wonder what He could've mean by THAT? I guess "some" will understand what He meant, "many" - maybe even "most" won't see it.
"...for wide is the gate and broad is the way that leads to destruction, and there are many who go in by it. Because narrow is the gate and difficult is the way which leads to life, and there are few who find it." (Matthew 7:13-14 - that very same Sermon on the Mount where He said "not one yod or tiddle" would change, at least 'till He finished the speech.)
If "salvation" was so trivial that all it took was mouthing a few words, then why did He (and His 'taught-ones') spend so much time issuing warnings about "false christs" and "false prophets," and "see that you are not deceived"?
SO, just because you asked so nicely this time, Zec, I will venture an OPINION:
If people are duped into worshipping "another jesus, who [Paul and company] did not preach" --
instead of the real "Salvation of YHVH" then perhaps they have a concern.
NO - let me be VERY clear:
I am NOT telling ANYONE that they are, or are NOT, "saved."
Just that there are enough clear warnings in Scripture, and enough "fake" out there, that there is a reason we are told to "work out your own Salvation with fear and trembling."
And a 'jesus' who allegedly re-wrote his own 'word' to outlaw something - polygyny, patriarchy, and His Instruction about marriage - that was literally the foundation of His people, is a prime candidate for such a fake. IMHO.
It’s a logical fallacy and doesn’t make a case for what people should actually believe.