But a natural man does not accept the things of the Spirit of God, for they are foolishness to him; and he cannot understand them, because they are spiritually appraised.1 Corinthians 2:14(NASB)
Paul gives a description of two types of Christians - the spiritual and the carnal. One is walking in spiritual and truth while the other is functioning in the flesh or under the law. One is dying to self while the other is living for self. One is being led and guided by the Holy Spirit while the other is resisting, quenching or grieving the Spirit of God. One is maturing in the faith while the other remains a spiritual baby, who is foolishly embroiled in worldly pursuits and fleshly desires. One will be rewarded with gold, silver and precious stones at the judgement seat of Christ, while the other will suffer loss - eternally saved but having forfeited any spiritual reward for good works.. carried out in the power of the Spirit, which God prepared for them to do in this life.
But Paul also gives a description of the natural man.. the unsaved man - the unregenerate man - the sinner who has not turned from their sin and trusted Christ for salvation. Paul calls the unbelieving man or woman.. who is dead in their trespasses and sins, and has not accepted the free gift of grace, by faith in Christ's finished work at Calvary - the natural man.
The natural man is wise in his own understanding but rejects the message of the cross as foolishness The natural man proudly glories in his own abilities, intellect, education, skills, philosophies and wisdom - and yet the natural man is a fool in the sight of God, Who labels his flawed intellect, godless world-view, selfish pride and human philosophies as foolish folly.
Paul points out that the foolishness of God is wiser than the wisdom of the sinful-man and the weakness of God is stronger than strength of the unsaved man: for a natural man does not accept the things of the Spirit of God, for they are foolishness to him. The unsaved man cannot understand the wisdom of God, because God's ways are above the way of man and are spiritually appraised and spiritually discerned - through the power of the Holy Spirit of God.
Irrespective of their intellectual capacity, expansive knowledge, impressive qualification or amazing accomplishments, the unregenerate man cannot ever receive the things of God. The Spirit is seeking to convict the sinner of sin and righteousness and judgement so that he will turn from his unbelief to faith in Christ and be born anew.. but until that happens the one who is dead in their trespasses and sins is incapable of receiving spiritual truth, spiritual knowledge, spiritual wisdom and spiritual understanding - for the things of the Spirit are spiritually discerned - through the promptings and power on the indwelling Holy Spirit.
Satan is the one that influences and energizes the unsaved man, and he has blinded their minds to trusting in the glorious gospel of God and until a sinner is convicted of their sin and guilt before a holy God and turns from the lie to the truth - by faith, they will remain blind and deaf to spiritual things - for the natural man does not accept the things of the Spirit of God, for they are foolishness to him - he cannot understand them, because they are spiritually discerned.
Heavenly Father, thank You that You convicted me of my sin, of Christ's righteousness and of judgement, which has been passed on all who do not by grace through faith come to trust in Christ as Saviour. Help me to live a spiritual life and not revert back to carnal pursuits and worldly ways, but may I walk in spirit and truth in the power of Your Holy Spirit and may I grow in spiritual wisdom and discernment day by day to Your praise and glory, AMEN.