The heart.

The heart is deceitful above all things, and desperately sick; who can understand it? " I the Lord search the heart and test the mind, to give everyman according to his ways, according to the fruit of his deeds. " Jeremiah 17:9-10

"Pay attention, my child, to what I say. Listen carefully. Don't lose sight of my words. Let them penetrate deep within your heart, for they bring life and radiant health to anyone who discovers its meaning. Above all else, guard your heart, for it affects everything you do."
Proverbs 4:20-23

Wonder how sometimes the slightest things that happen in a day get us beaten down? When doubt slips in so silently? When condemnation comes so naturally? When the joy God has put in our hearts dissipate so quickly?

"Above all else"I used to wonder why God used those words of such great emphasis. I think I get it now.

"Guard it with your life."