If man's spirit is dead then what quickens man's flesh? you can bet on mans spirit being very much alive as long as the man is alive. We cannot live with out our spirit.
MB
Is God wrong?
Ephesians 2:1-3 And you were dead in the trespasses and sins in which you once walked, following the course of this world, following the prince of the power of the air, the spirit that is now at work in the sons of disobedience— among whom we all once lived in the passions of our flesh, carrying out the desires of the body and the mind, and were by nature children of wrath, like the rest of mankind.
This isn't a matter of "if man's spirit is dead", it is a matter of "since man's spirit is dead."
Man cannot and will not choose to run toward God. Man cannot and will not repent and submit to God. Man will, by his very nature, rebel and hate God's supremacy. Unless God chooses to intervene in a human's life, that person will naturally be antagonistic toward God and rebel.
It is a foolish, biblically false, claim to suggest that men willfully choose God. Men do not.
God must quicken their, dead in trespasses and sins, spirit and regenerate what was lost.
2 Corinthians 5:13-21 For if we are beside ourselves, it is for God; if we are in our right mind, it is for you. For the love of Christ controls us, because we have concluded this: that one has died for all, therefore all have died; and he died for all, that those who live might no longer live for themselves but for him who for their sake died and was raised. From now on, therefore, we regard no one according to the flesh. Even though we once regarded Christ according to the flesh, we regard him thus no longer. Therefore, if anyone is in Christ, he is a new creation.The old has passed away; behold, the new has come. All this is from God, who through Christ reconciled us to himself and gave us the ministry of reconciliation; that is, in Christ God was reconciling the world to himself, not counting their trespasses against them, and entrusting to us the message of reconciliation. Therefore, we are ambassadors for Christ, God making his appeal through us. We implore you on behalf of Christ, be reconciled to God. For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God.