That is what makes the difference, it changes behavior. Head knowledge cannot save if the heart does not believe. Easy for God to know who believes with their heart, and who does not. What does your heart believe?? This is the word of faith.
“The word is near you, in your mouth and in your heart”—that is, the word of faith which we are preaching, that if you confess with your mouth Jesus as Lord and believe in your heart that God raised Him from the dead, you will be saved; for with the heart a person believes, resulting in righteousness, and with the mouth he confesses, resulting in salvation. For the Scripture says, “Whoever believes in Him will not be put to shame.” (Romans10:8-11 NASB)
With the heart a person believes and begins the process of being changed into Jesus’ likeness. Changed! Restoring what Adam lost in the garden and so much more. Life. For the heart that believes, believes Jesus when He said, “The thief comes only to steal and kill and destroy; I came so that they would have life and have it abundantly.” (John 10:10 NASB) Apostle Paul explained the results of a believing heart this way.
“But we all, with unveiled faces, looking as in a mirror at the glory of the Lord, are being transformed into the same image from glory to glory, just as from the Lord, the Spirit.” (2 Corinthians 3:18 NASB)