That which is born of the flesh is flesh, and that which is born of the Spirit is spirit. John 3.6

Those who are born of the flesh embrace religions, including evangelical, but do not obey the Word of God. Their nature remains the same.

Like irrational animals, those born of the flesh have an irrational nature; they are unable to comprehend the spiritual things.

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. I Corinthians 2.14

Those born of the Spirit are spiritual. Their human nature is transformed to a godly nature. They are able to listen, understand, and obey the Voice of the Spirit of God.