"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."
In context... the natural man does not receive spiritual teachings!
While the Gospel was designed to reach the natural man!
The Gospels were designed to appeal to the natural emotions and thinking of a man.
In contrast to the Gospels, teaching on the deity of the Trinity was not designed to reach the natural man.
Some have come to believe that the Gospel is a spiritual teaching, when in fact, it has been presented as having
great appeal (potentially) to the natural man's way of thinking and emotions.
What we seek to learn after regeneration is teachings to feed our new found heart.
The Gospels, in contrast. is for people to feed their need to find solace in their lives.
Its a fine line there