"Faith is a spiritual faculty, not a natural faculty. Believing is the activity of this spiritual faculty. Faith is a spiritual faculty that affects the whole soul. If a man is an unbeliever, he is an unbeliever with his mind, with his will, with his desires, with his whole being. If a man is a believer, he is a believer with his whole being. Faith, therefore, is that faculty that affects the whole soul-life of the believer. It is the faculty by which the soul cleaves to God. This the natural man does not do. The natural man turns away from God, but the believing soul cleaves to God. For this reason, insofar as faith affects the mind, it is a certain knowledge of God. Insofar as it affects the heart, it is the letting down of one's self on this God. This is confidence. Believing on God is that act of the believing soul whereby the soul lets itself down on the God of salvation, believing that God will do us nothing but good". ~ Herman Hoeksema
From: Righteous by Faith Alone: A Devotional Commentary on Romans, page 172, on Romans 4:23- 24. Available at the Reformed Book Outlet in Hudsonville MI (closed Sundays).