Discernment is a Gift
not a skill to be learned.
1 Corinthians 12:8-10
For to one is given by the Spirit the word of wisdom; to another the word of knowledge by the same Spirit; [9] To another faith by the same Spirit; to another the gifts of healing by the same Spirit; [10] To another the working of miracles; to another prophecy; to another discerning of spirits; to another divers kinds of tongues; to another the interpretation of tongues:
1 Corinthians 2:14
But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.