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.
1 Cor 2:14 speaks of the things of the Spirit of God. That is not referring to Jesus Christ and Him crucified (1 Cor 2:2) which Paul taught to the church at Corinth.
The things of the Spirit of God in 1 Cor 2:14 refers to the wisdom of God in a mystery (1 Cor 2:7) which Paul was able to discuss among them that are perfect (perfect meaning those who were more spiritually mature – 1 Cor 2:6).
1 Cor 2:1-5 tells us the things Paul taught to those who were not yet born again and those who were born again yet still young in faith:
1 Corinthians 2:
1 And I, brethren, when I came to you, came not with excellency of speech or of wisdom, declaring unto you the testimony of God.
2 For I determined not to know any thing among you, save Jesus Christ, and him crucified.
3 And I was with you in weakness, and in fear, and in much trembling.
4 And my speech and my preaching was not with enticing words of man's wisdom, but in demonstration of the Spirit and of power:
5 That your faith should not stand in the wisdom of men, but in the power of God.
In vs 2, Jesus Christ, and Him crucified is the gospel. The gospel of Christ is the power of God unto salvation (Rom 1:16). Once a person believes the gospel, he/she is born again; however, those still young in faith are to feed on the sincere milk of the word that [they] may grow thereby (1 Peter 2:2).
In 1 Cor 2:6 and following, Paul tells us about the things which he taught those who were more spiritually mature ... the wisdom of God in a mystery, even the hidden wisdom.
It is these deep things of God (1 Cor 2:10) to which 1 Cor 2:14 refers when it speaks of the natural man's inability to receive:
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.
I do not believe the gospel is difficult for natural man to comprehend. The Lord Jesus Christ died for our sins, He was buried and rose again the third day. That is not a difficult concept. The natural man hears the gospel and he/she either believes the gospel and is born again or he/she suppresses the truth in unrighteousness (Rom 1:18) and is not born again.
The wisdom of God in a mystery which if the princes of this world had known they would not have crucified the Lord of glory (1 Cor 2:6-8), is a more complex spiritual truth which is addressed in 1 Cor 2:14 which the natural man does not comprehend.
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