There are times when I can only rely on my heart. My head might be screaming an entirely different message at me. But my heart knows the truth of God's word because I've hidden it deep inside my heart. So when life doesn't add up and/or my flesh is weak I hold onto the confidence I have in God and His keeping power. The 'soundness' of His Holy Scriptures anchor me and make me strong where/when I am weak. His love and His word are my hope and my confidence in the good times and the testing times.
My heart is fixed, O God, my heart is steadfast and confident! I will sing and make melody. Psalm 57:7