We are told in the chapter of which the text is a part (John 3) that that which is born of the flesh is flesh, and that which is born of the Spirit is spirit; which teaches us that there is nothing truly spiritual or holy in the first birth, but that this comes by the second, or by the renewings of the Holy Ghost. Christ tells the Jews that they hated Him without a cause. And the inspired apostle says that "the carnal mind is enmity against God, for it is not subject to the law of God, neither indeed can be. So then, they that are in the flesh cannot please God." (Rom 8:7-8) Therefore, seeing this is the state that mankind are antecedent to the new birth, it is not fit or reasonable that God should bring them into favor with Himself, or be at peace with them, without regeneration. Nay, He cannot, consistent with His perfection, for this would be for Him to connive at wickedness when He tells us that He can by no means clear the guilty. And to suppose that sinners can see the kingdom of God or be happy in the divine favor without regeneration or the new birth, is a perfect inconsistency, or contrary to the nature of the thing. The very essence of religion consists in love to God, and a man is no further happy in the favor of God than he loves God. Therefore, to say we enjoy happiness in God, and at the same time hate God, is a plain contradiction. "
- "May We Meet in the Heavenly World: The Piety of Lemuel Haynes" Thabiti Anyabwile
"The Necessity of Regeneration"by Lemuel Haynes