Isaiah 45:17
But Israel will be saved by Jehovah with an everlasting salvation. You will not be put to shame or disgraced for all eternity.
Acts 4:10-12
let it be known to all of YOU and
to all the people of Israel, that
in the name of Jesus Christ the Naz·a·reneʹ, whom YOU impaled but whom God raised up from the dead, by this one does this man stand here sound in front of YOU. 11 This is ‘the stone that was treated by YOU builders as of no account that has become the head of the corner.12 Furthermore,
there is no salvation in anyone else, for there is not another name under heaven that has been given among men by which we must get saved.”
Isaiah gives the name of who will save Israel. Acts gives a completely different name. Proof positive for a false prophet.
The speaker of the words in Acts 4 ( if it actually occured ) is saying "There is no other name ... There is no salvation in anyone else ... except Jesus Christ." That is a complete contradiction with Isaiah and so many other verses in the Hebrew bible. A person might, maybe, be able to get away with saying "This name also saves." But saying "this name and this name only saves", that is false prophet territory. According to Acts, again, if it's true, the speaker had performed wonders, but now is preaching for a different god, is promoting a different god, with a different name, and inciting others to follow this other god. If you review Deuteronomy 13, you'll see, someone behaving like this is a test. It is someone for the Jewish people to forceably remove without mercy.