Any doctrine not in strict agreement with God's Word would be apostasy........satanic, even if yu go so far as to say there are other doctrines, e.g. man's or Satan's, either is not of God.
Well you're wrong about that. And like the typical Christian, you don't know what apostasy is.
There's plenty of gray area in the NT. As long as they were not promoting damnable heresies, false teachers were not immediately expelled from Church. They were given a warning and a second chance, meanwhile, the congregation was urged to avoid them.
Learn something from Paul...
Philippians 1:14-18
And many of the brethren in the Lord, waxing confident by my bonds, are much more bold to speak the word without fear. And many of the brethren in the Lord, waxing confident by my bonds, are much more bold to speak the word without fear. Some indeed preach Christ even of envy and strife; and some also of good will: The one preach Christ of contention, not sincerely, supposing to add affliction to my bonds: But the other of love, knowing that I am set for the defence of the gospel. What then? notwithstanding, every way, whether in pretence, or in truth, Christ is preached; and I therein do rejoice, yea, and will rejoice.
Paul knew that because he was imprisoned some were bold and fearless preaching Christ, but some who were preaching Christ wanted to outdo Paul and were trying to build a name for themselves. Some were not sincere and were preaching Christ selfishly and with wrong motives. Even when the gospel was not being preached in complete truth and distorted, Paul was still able to rejoice knowing that Christ was being preached!