Core Biblical Doctrines must exist, or you’re simply not one of the Lord’s people.
Yet the Lord’s people are to try to obtain to the example in Ephesians 4: v 2-3 which is speaking about having unity in the spirit, (when we are baptized into Christ) at Salvation, and then as we grow and move forward.
Anything which detracts from such a teaching is simply heretical and dangerous to the flock.
Brethren may be corrected and encouraged in love, but they should never be rejected by personal judgmental-ism because of personality conflicts. As unity (even for the spiritually mature) must be diligently preserved as: Ephesians 4 vs 13 instructs, (until we attain to the “fullness of Christ”).We are to strengthen each other, until the day we meet with the Lord – and not destroy: unless of course false doctrines are being taught as destructive to the faith – known as heretical doctrines which we are to reject.
It is important that one understands the very serious nature “of thinking they have gotten beyond sin”, as this is Pharisaic, proud and destructive to the grace of the Lord; not only within one’s own life, but in the life of others!
These type of “Lordship Salvation teachings” can be very deceptive, and helps to destroy the faith and unity of actual brethren. It may actually drive many away from the faith, if this heretical type of teachings persists within a fellowship. The Bible instructs us to remove that heretic (reject) from the faithful, after being warned by the other Elders; in the case they refuse to repent. This is also why accountability to other elders is extremely important, Biblically speaking.
Below is a podcast which I have found very useful, it speaks about personality conflicts and healthy relationships within the body of Christ. It is important to know the sound doctrines of the faith as not to be deceived by false teachings.