The difference

"Then you shall again discern between the righteous and the wicked, between one who serves God and one who does not serve Him." Malachi 3.18

Those who are born of the Spirit are essentially different.

If a person says he or she is a child of God but their behaviour is not different from those who live according to the course of this world, they are deceiving themselves.

Those who are born of the Spirit bear the image of God Almighty, that is, His character.

The only way the world will see and know the invisible God is through His children.

As Jesus said, "Who sees Me sees the Father."

Perverse heart

“The heart is deceitful above all things, and desperately wicked; who can know it?" Jeremiah 17.9

Even though it is known that the heart is wicked, misleading, corrupt and a faithful ally to the devil, still, its feelings, emotions, pleas and cries are heard and heeded.
Why?
Because those who have it like that are not yet born of the Holy Spirit.

Limited by the heart

"You are not restricted by us, but you are restricted by your own affections." 2 Corinthians 6.12

Most people have been limited by the feelings of the deceiving heart. Faith gets stuck in time and gets old...
That is why one needs to be born of the Spirit and become a new creature. A spiritual creature who does not walk by visible things, but by the invisible, which are eternal.

Remains

"But the anointing which you have received from Him abides in you, and you do not need that anyone teach you; but as the same anointing teaches you concerning all things, and is true, and is not a lie, and just as it has taught you, you will[a] abide in Him." 1 John 2:27

The Holy Spirit comes upon those who are sincere to be guided according to His will, so that they may not be taught by deceiving spirits. This is the anointing that teaches.