I would add another biggie to the author’s list:
Teach them Once Saved Always Saved for the ultimate feel-good pride fix.
Or you could teach them that belonging to the one Proudest and onliest church will make them a Christian, you know, sort of like how whenever I sleep in the garage, I turn into an automobile.
Nonsense D-Fender....but there is the sanctity of the believer....and we are sealed by His Holy Spirit until that coming day.
Eph 1:13 ....In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise.
1Pet 1:23.... Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever.
JESUS PRAYED,.... "I pray not that thou shouldest take them from the world, but that thou shouldest keep them from the evil one.... They are not of the world even as I am not of the world..... Sanctify them in the truth: thy word is truth."... John 17:15-17
So yes it's quite possible to know one is saved as scripture attests to just that.