He saith unto them, But whom say ye that I am? And Simon Peter answered and said, Thou art the Christ, the Son of the living God. And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven. - Matthew 16:15-17
A lot of folks have made it their business to study doctrine, contend for it, maintain a zeal for it, and even defend it. They are religious professors, but not possessors. You see, the professor, they receive doctrines because they know that to be accepted within their chosen camp, they must profess certain doctrines to maintain their perceived status. You see this all the time regardless of the religious camp. You see it even in politics.
Salvation possessors, however, they not only receive the doctrine of Christ, but they actually see and comprehend. And they also experience Christ within their heart. This possession is a result of the Holy Spirit revealing the truth to them. These possessors, they come to the truth through much trial and tribulation. They know what it's like to be a sinner. They feel it in their bones how rotten and evil they are without the Lord's righteosness. Like Adam and Eve in the Garden, they sense their utter nakedness, and long for robes to cover them. And they come burdened by guilt to calvary because they are utterly unable to flee to anywhere else.
The professor has an outward appearance. But the possessor has an inward reality. They may look the same to a casual observor, but they are worlds apart. Being able to regurgitate the latest talking points does not make one a possessor. True possession of salvation in Christ requires an act of sovereign grace.