I 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.”
I have observed that “the things of the Spirit of God” are indeed “foolishness” to “the natural man”. We believe and understand “things” when we have a reference for them in our mind; for, in learning, we compare new things that are presented to us to things that we already know. A good teacher will learn about the experiences of their students; for, these experiences (things they have already learned) form a reference to which new “things” are compared. The Lord used this form of teaching when He told Peter, “I will make you fishers of men” (Matthew 4:19). Peter, and some of the other Apostles, were professional fishermen, they understood fishing. So, The Lord compared Apostolic evangelical preaching to fishing, and they understood; it would be their duty to preach the Word of God and to bring in those who took the Gospel Bait. But, “the things of the Spirit of God” have no point of reference within the “natural man”; so, these things are “foolishness” to him. But, when the Holy Spirit, gives a person Spiritual Birth, He plants “faith” within the person, which comes with the necessary “substance” and “evidence” (Hebrews 11:1) to learn and understand and rejoice in “the things of the Spirit of God”. Paul calls this “comparing spiritual things with spiritual” (I Corinthians 2:13); that is, when we hear “the things of the Spirit of God”, our mind immediately compares “the things” we hear to the “spirit” (“substance” and “evidence”) that is already in us. Similarly, a person that does not have “faith” cannot understand “faith”; for, “the righteousness of God” is “revealed from faith to faith” (Romans 1:17); that is, “revealed” and compared to the “faith” that God placed within a person at the moment He gave them Spiritual Birth (Regeneration). So, when we come across those who summarily reject “the things of the Spirit of God”, we simply “depart” and “shake off the dust of” our “feet.” (Matthew 10:14). But, like “Saul” (“Paul”), there may come a day when the Lord will give them Spiritual Birth (Acts 9:3-6) and then they will the rejoice in “the things of the Spirit of God”!