When God takes away the heart of stone and gives an heart of flesh— then God grants repentance. A new heart is a penitent heart. Regeneration is necessary because sinners have hard, impenitent hearts. And this is the glorious effect of the power of God in the act of regeneration. It reduces the rebel into submission. It melts the stubborn heart into repentance. When God regenerates and grants repentance, he does it by one decisive act. (Repentance, 63)