Ezekiel 36:26-27

Moreover, I will give you a new heart and put a new spirit within you, and I will remove the heart of stone from your flesh and give you a heart of flesh.  I will put my Spirit within you and cause you to walk in My statutes and you will keep My ordinances and do them. 

When Adam and Eve sinned against God in the garden, their hearts hardened with sin. They lost the connection, guidance, and knowledge of God. They needed a new heart to regain what they lost. Jesus came to restore our relationship with God and restore our hearts. It is up to us to keep it protected and focus on Jesus. Sin may knock at our door, but we don’t have to answer.