Ecclesiastes 2:3 I searched in my heart how to gratify my flesh with wine, while guiding my heart with wisdom, and how to lay hold on folly, till I might see what was good for the sons of men to do under heaven all the days of their lives.
Proverbs 4:23 Keep your heart with all diligence, For out of it spring the issues of life.
1 Corinthians 2:11 For what man knows the things of a man except the spirit of the man which is in him? Even so no one knows the things of God except the Spirit of God.
1 Corinthians 13:11 When I was a child, I spoke as a child, I understood as a child, I thought as a child; but when I became a man, I put away childish things.