Much of our mental suffering comes from how tightly we hold our beliefs. In the monastery my teacher Ajahn Chah used to smile and ask, "Is it true?" He wanted us to learn to hold our thoughts lightly.

Within the stillness of meditation we learn to observe how words and images arise and then vanish. When we let thoughts come and go without clinging, we can use thought, but we rest in the heart. - Jack Kornfield, The Wise Heart