Total depravity of the flesh
Continuing from Part 1, the flesh generates desires only on the basis of pleasure and pain to itself, namely the body made of dust. Accordingly, it has desires of the flesh (that which physically and empirically gives pleasure or reduces pain), desires of the eye (that which can mentally give pleasure in the imaginations), and the pride of life (that which gives pleasure in the self-accomplishment of certain desires). Nowhere does the flesh account for the desires of God which is why it can never be pleasing to God (Rom 8:8).
Accordingly, if the flesh is persistent enough in its demand for its own desires, then man’s conscience can be suppressed, the mind can make the wrong associations and get darkened accepting these erroneous desires, and the heart could hold falsehood within it. When the heart already holds more false beliefs than true, God’s own desires get rejected for they are seen as a contradiction to what’s already held inside. This way, the heart is hardened against the truth.
God’s commands are given repeatedly to man, exhorting him to deny his self-nature and trust in God for his whole system is compromised, but the flesh asserts itself in between and crowds out God’s desires. On a side note, God hardens hearts just by commanding more of His Holy ways without providing the mercy and grace for the creature to obey.
Regeneration
This is where the supernatural work of God’s regeneration cleans house (Luk 11:25). By His power, He shines His light into this darkened mind and takes away the hardened heart and gives a new heart. This is the Gospel’s piercing truth that when applied by the power of the Holy Spirit, convicts man in his innermost by exposing all the falsehood and erroneous ways he’d been blinded to until then. All the falsehood falls when exposed and God’s truth is received.
Considering the non-elect man, he is now enabled irresistibly to acknowledge the glory of Christ and the futility of his own nature. He is now commanded to continue believing in the arm of the Lord and not the arm of the flesh – and God even provides the power and gifts of the Holy Spirit to aid him. But non-elect man is still in his self-determining flesh and it self-determines to go back to the dirt (2Pet 2:22) and fall away from God’s truths because its desires are still continually evil even when God has provided all that’s needed for life in the Gospel of Christ – and the condemnation that follows is justly deserved with no more sacrifice for sins or renewal again to repentance. These have tasted the heavenly gift and were partakers of the Holy Spirit but will be denied by the Lord saying, I never knew you.
Rebirth
The only difference between the elect and the non-elect lies in God’s own nature/spirit operating within the elect compared to man’s own self-nature/flesh self-determining in the non-elect. God regenerates the elect likewise in giving a new heart and renewing the mind through conviction of sin. God then additionally tears open the elect’s flesh as the temple veil was torn (Heb 10:20) and gives access to His own most Holy presence by birthing them in the spirit by the power of His Holy Spirit (John 3:6). Now, the elect man need not be taught by others for he is taught by God Himself dwelling within him, ie the inner man.
God’s nature generates holy desires that have the power to overcome his decaying outer man/flesh’s lusts. And not just in desiring, but in working out God’s desires in might and power, God gives the Holy Spirit as in the Pentecost to seal the elect’s salvation with a guarantee – and so the spirit is willing and strong, no longer dependent on weak flesh. In this, God demonstrates His preserving and saving power when His own nature is operational to when man self-determines his ways. And so, we shall all be gods in the resurrection (John 10:34-35), because we shall all have Christ’s own nature operational in us, completely conformed to His image, having our own self-natures/flesh destroyed in the fires of condemnation.