I apologize for my tardy response. Other responsibilites have pulled me away from the these discussions I love. I am encouraged that we find areas of agreement.
I too believe that the natural man is one completely without Christ. I don't believe it is possible for the natural man to set his/her mind on the things of the Spirit of God, for he/she is without the Spirit. 1Co 2:14 not only tells us that the things of the Spirit of God are foolishness to the natural man, but also that he cannot know the things of the Spirit, for these things are spiritually discerned. So how can the natural man set his mind on things of the Spirit without the Holy Spirit guiding him?
1Co 2:14... neither can he know them, because they are spiritually discerned.
Natural man cannot know the things of God without the Spirit of God teaching him.
1Co 2:11 For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God.
1Co 2:12 Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God.
1Co 2:13 Which things also we speak, not in the words which man's wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual.
Once we have been born again by the Spirit of God, we struggle against the flesh, which desires to follow the natural things, or the spirit of this world, but that struggle is what tells us that we are no longer natural man. For natural man has no struggle against the Spirit. How could he have since he does not have the Spirit of God?
The choice to obey and receive promises came with stipulations...do this and live, disobey and die. The nation as a whole (except the remnant) remain in unbelief, even after telling Joshua they too chose to serve the LORD. Was it ever God's promise to the whole nation that they would receive eternal life for obedience to His law? Every promise God made to national Israel has been fulfilled. His promise to save a remnant for eternal life was fulfilled in Christ.
Joh 3:3 Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God.
Joh 3:5 Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God.
How can we know to make a free will decision to follow Him without the indwelling Spirit?
Ro 10:17 So then faith cometh by hearing, and hearing by the word of God.
We are spiritually dead in trespasses and sins until we "hear" the Word of God. After "hearing" we receive faith to believe, having faith to believe, we freely choose to turn to Christ that we might have life, repenting of our sins. Without faith it is impossible to please God.
Heb 11:6 But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him.
Men don't understand this, and find great offense in God choosing to save only some men. They cry "unfair"... I see that as looking at God from a very negative perspective. Because I see a God of great love, mercy, grace and compassion for those whom He has elected to save. No man deserves this great love and mercy God bestows upon His people, but praise God that He saves any man.