The main point of correlation these false Gospels have is that they do not require believing all of Christ words, and abiding in them, for salvation.
When Christ said:
"Enter through the narrow gate;" (of believing faith in Christ), " for the gate is wide" (of unbelieving Christ words) "and the way is broad" (full of sin) "that leads to destruction, and there are many who enter through it."
"For the gate is small" (believing all of Christ words) "and the way is narrow" (of denying self sin) "that leads to life, and there are few who find it." Matthew 7:13-14
The true Lord Jesus Christ foresaw the false Gnostic gospels that strewn the land, would all say, "Sin is a necessity!" Holding onto some aspect of former sinful self by not believing all Christ words is needful for easy believeism.
The dangerous implication of dying in that kind of natural thinking is Christ said:
"The one who rejects Me and does not receive My words has the one judging him: the Word which I spoke, that will judge him in the last Day." John 12:48
The truth is, one can have eternal life with Christ, but it will cost them living in the grace of God that makes them deny their former life of daily abiding in sin.