1 Timothy 6:2-3 BSB
“3 If anyone teaches another doctrine and disagrees with the sound words of our Lord Jesus Christ and with godly teaching, 4 he is conceited and understands nothing. Instead, he has an unhealthy interest in controversies and semantics, out of which come envy, strife, abusive talk, evil suspicions”
The test of a genuine Christian is in what they believe, teach, and preach. If they adhere to another doctrine, alienated from that which Christ preached, and reject the core and fundamental message of the gospel with the rest of the New Testament, it reveals their spiritual condition. Tread lightly from such people, or they may entrap your soul with deceptive words.