Not according to Christ in Matt 7 "Lord Lord did we not.... in your name?" Then Jesus says "not everyone who says Lord Lord ... will enter". The fail of "I don't think Christ is savior any more" certainly would be a mistake - but Matt 7 does not put any blame at all on the "words being said".
In cases where multiple popes raised their own papal armies and the armies fought each other - neither army would claim they did not know Christ was the Savior of mankind. Still they were dying for a cause ...
It is almost never the claim "because Christ is not the Savior" or "Christ is not Messiah" in those cases.
Annabaptists were killed -- but not because "They thought Chris was not the savior"
"By 1566, roughly
3,000 Anabaptists were killed because of their faith. Some Anabaptists fled from the Netherlands to England to escape persecution, but even here they risked coming to the same fate as in Europe. Two Anabaptists were burned at the stake in 1575 in London."
The Anabaptists.
History does not confirm the suggestion that the only life-death deception/errors leading one group exterminating another - and another group dying for their convictions within Christianity - was "Christ is not the savior"
Yet scripture points to an even greater power and deception with "signs and wonders" at the end of time.
IN Mark 7:6-13 Jesus does not say their doctrinal error was lack of belief in he Messiah - in the sola-scriptura argument that he makes there.
as noted here in post #17
It is interesting in Mark 7 that Jesus did not say "false doctrine about the Messiah" though they certainly had that problem "as well".