1 Chronicles 28:9

And thou, Solomon, my son, know thou the God of thy father, who had so often helped David out of his troubles, and serve Him with a perfect heart, with undivided allegiance, and with a willing mind; for the Lord searcheth all hearts and understandeth all the imaginations of the thoughts, wherefore a mere hand and lip service cannot deceive Him. If thou seek Him, desiring His inner acquaintance in true love and service, He will be found of thee; but if thou forsake Him, He will cast thee off forever, this being the manner employed by the Lord to this day; He wants heart-service, not mere head-knowledge.