Satan blinds people.
Recall; Jesus said to Peter, "flesh and blood has not revealed this to you" (Mat. 16:16-17)
Also recall; A natural(Carnal) man does not recieve the things of the spirit of God (1Cor. 2:14), it will look foolish in his eyes
YES. VERY DIFFICULT..AND VERY SAD...BUT EVERYONE HAS THE FREEDOM TO HIS/HER OWN DECISION.