The Spirit of God “seals the deal” in regenerated man’s heart.
And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth. (John 1:14 KJV)
The Word is none other than Jesus Christ. Yes, Jesus was created in the flesh and born upon this earth to an earthly virgin mother, Mary; and to His heavenly Father God. Jesus was supernaturally conceived through the power of God the Father to live a short time on this earth.
Jesus was alive just like you and I are alive in our tent of flesh today. However, Jesus was without sin. Jesus was tempted by the devil as we are tempted too but did not succumb to sin. Jesus was filled with the grace and Truth of God and perfect and spiritually flawless before God.
When mankind allows God to fill his heart to overflowing with His grace and Truth it is a sealed deal! Man’s heart is impenetrable to the dark evil nature of the god of this world. Jesus is perfect proof that having God’s nature and Spirit living inside of us brings about a glorious life. It is a life pointing to God as we live practically day to day in a spiritual walk in fellowship with Him.