natural man
1 Corinthians 15:44 It is sown a natural body, it is raised a spiritual body. There is a natural body, and there is a spiritual body. 45 And so it is written, "The first man Adam became a living being." The last Adam became a life-giving spirit. 46 However, the spiritual is not first, but the natural, and afterward the spiritual.
The natural man is the unregenerate
John 3:3 Jesus answered and said to him, "Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God."
Romans 7:18 For I know that in me (that is, in my flesh) nothing good dwells; for to will is present with me, but how to perform what is good I do not find.
receiveth not (though they are offered to him, and are "worthy of being received by all men")
1 Timothy 1:15 This is a faithful saying and worthy of all acceptance, that Christ Jesus came into the world to save sinners, of whom I am chief.
they are foolishness unto him
1 Corinthians 1:18 For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God. 19 For it is written: "I will destroy the wisdom of the wise, And bring to nothing the understanding of the prudent." 20 Where is the wise? Where is the scribe? Where is the disputer of this age? Has not God made foolish the wisdom of this world? 21 For since, in the wisdom of God, the world through wisdom did not know God, it pleased God through the foolishness of the message preached to save those who believe. 22 For Jews request a sign, and Greeks seek after wisdom; 23 but we preach Christ crucified, to the Jews a stumbling block and to the Greeks foolishness, 24 but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God. 25 Because the foolishness of God is wiser than men, and the weakness of God is stronger than men. 26 For you see your calling, brethren, that not many wise according to the flesh, not many mighty, not many noble, are called. 27 But God has chosen the foolish things of the world to put to shame the wise, and God has chosen the weak things of the world to put to shame the things which are mighty; 28 and the base things of the world and the things which are despised God has chosen, and the things which are not, to bring to nothing the things that are, 29 that no flesh should glory in His presence. 30 But of Him you are in Christ Jesus, who became for us wisdom from God--and righteousness and sanctification and redemption-- 31 that, as it is written, "He who glories, let him glory in the Lord."
neither can he
1 Corinthians 2:10 But God has revealed them to us through His Spirit. For the Spirit searches all things, yes, the deep things of God. 11 For what man knows the things of a man except the spirit of the man which is in him? Even so no one knows the things of God except the Spirit of God. 12 Now we have received, not the spirit of the world, but the Spirit who is from God, that we might know the things that have been freely given to us by God. 13 These things we also speak, not in words which man's wisdom teaches but which the Holy Spirit teaches, comparing spiritual things with spiritual. 14 But the natural man does not receive the things of the Spirit of God, for they are foolishness to him; nor can he know them, because they are spiritually discerned. 15 But he who is spiritual judges all things, yet he himself is rightly judged by no one. 16 For "who has known the mind of the Lord that he may instruct Him?" But we have the mind of Christ.
John 16:13 However, when He, the Spirit of truth, has come, He will guide you into all truth; for He will not speak on His own authority, but whatever He hears He will speak; and He will tell you things to come. 14 He will glorify Me, for He will take of what is Mine and declare it to you.
Ephesians 2:1 And you He made alive, who were dead in trespasses and sins, 2 in which you once walked according to the course of this world, according to the prince of the power of the air, the spirit who now works in the sons of disobedience, 3 among whom also we all once conducted ourselves in the lusts of our flesh, fulfilling the desires of the flesh and of the mind, and were by nature children of wrath, just as the others.
Ephesians 4:20 But you have not so learned Christ, 21 if indeed you have heard Him and have been taught by Him, as the truth is in Jesus: 22 that you put off, concerning your former conduct, the old man which grows corrupt according to the deceitful lusts, 23 and be renewed in the spirit of your mind, 24 and that you put on the new man which was created according to God, in true righteousness and holiness.
