The heart is one’s core. According to Scripture, it is who you and I are at our deepest and most private level. So profound is the hidden person of the heart that only God Himself is able to plumb its unfathomable depths. The psalmist declared, “O Lord, You have searched me and known me” (Psalm 139.1). For the believer, that is good news, because God is the ultimate heart-changer.
From: Minding the Heart: The Way of Spiritual Transformation by Robert L. Saucy (Grand Rapids: Kregel Publications, 2013), p. 13
Robert L. Saucy (1930-2015) taught systematic theology at Talbot School of Theology from 1961 until his death.