If people say they believe in Jesus as John 6:29 states, “believe in the one He has sent” but then turn around and deny God’s promises to Israel, or Bible prophecy, would they be examples of Jesus saying “I never knew you?” There are several teachers I’m aware of who claim Jesus as their Savior, and I think in their heart, they really believe Jesus is the Son of God. But then they turn other parts of the Bible around to suit their own opinions. Are they considered to be false teachers?
Believing in the one He sent (John 6:29) means believing that Jesus came to Earth to die for our sins so we could live forever in Heaven with Him. It wasn’t meant to include all the different doctrines of men that contradict God’s word. People who promote these non-biblical opinions will have to answer to God for the damage they cause (James 3:1) but it won’t endanger their salvation as long as they believe they’re saved exclusively by the blood of Jesus.
That said, I believe teachers who deny the sufficiency of the cross or promote an alternative path to salvation are in another category altogether and are clearly false teachers. Peter said, “They will paid back with harm for the harm they’ve done” (2 Peter 2:13)
And John said, “They went out from us, but they did not really belong to us. For if they had belonged to us, they would have remained with us; but their going showed that none of them belonged to us” (1 John 2:19). He was saying that even though they claim to be part of the church, their teaching proves they were never saved.
These are some of the ones to whom Jesus will say, “I never knew you. Away from me you evil doers” (Matt. 7:23).