God is omniscient. He knows all our thoughts (spoken and unspoken). Psalm 94:11 proclaims: “The LORD knows the thoughts of man” (“They are but a breath.”) Similarly, Psalm 139:2b says: “You discern my thoughts from afar.” God declares: “For I know the things that come into your mind” (Ezek 11:5). Amos 4:13a states: “He who forms the mountains and creates the wind, and declares to man what is his thought.” Additionally, God depicts his knowledge utilizing the image of the heart (mind): “Sheol and Abaddon lie open before the LORD; how much more the hearts of the children of man!” (Prov 15:11). And David wrote: “The LORD searches all hearts and understands every plan and thought” (1 Chron 28:9).

However, God does not simply observe passively but scrutinizes our intellectual activity—in real time, 24/7. Several terms are used to express this activity: “test,” “try,” “prove,” “search,” “search out,” and “examine.” The Lord declares: “I the LORD search the heart and test the mind” (Jer 17:10). Others testify about him: “The crucible is for silver, and the furnace is for gold, and the LORD tests hearts” (Prov 17:3); “Every way of a man is right in his own eyes, but the LORD weighs the heart” (Prov 21:2); “If you say, ‘Behold, we did not know this,’ does not he who weighs the heart perceive it?” (Prov 24:12); and “O LORD of hosts, who tests the righteous, who sees the heart and the mind” (Jer 20:12).

In the Old Testament mental piety appears in heartfelt petitions that invite divine testing. These are prayers for intellectual and motivational purification. David implored the Lord: “Prove me, O LORD, and try me; test my heart and my mind” (Psalms 26:2). Psalm 139:23 states: “Search me, O God, and know my heart! Try me and know my thoughts!” Psalm 19:4 declares: “Let the words of my mouth and the meditation of my heart be acceptable in your sight.”

Perhaps the most poignant expression of intellectual piety and redemptive epistemology is Psalm 131:1—2.

O LORD, my heart is not lifted up; my eyes are not raised too high; I do not occupy myself with things too great and too marvelous for me. But I have calmed and quieted my soul, like a weaned child with its mother; like a weaned child is my soul within me.

Do you, Christian thinker, pray this way also?