Out of the heart are the issues of life, Prov. 4:23.

And in religion the heart takes possession of

-the intellect, Rom. 10:13, 14; Heb. 11:6, of

-the feelings, Psa. 28:7; 30:12, and of

-the will, Rom. 2:10, 13; Jas. 1:27, 1 John 1:5-7.

The whole man is made subservient to God in every sphere of life. 

Berkhof