Behold, thou desirest truth in the inward parts (Psalm 51:6).

Sincerity is of utmost importance to a Christian. It is the sauce which seasons piety and makes it savory. Sincerity is the jewel that God is most delighted with.

To speak plainly—all our pompous show of holiness, without this soul of sincerity to enliven it—is but ‘pious folly’.

It is but going to hell in a more devout manner than others! My son, give me thine heart (Proverbs 23:26).

If the heart is for God, then our tears, our alms—all are for God. A godly man does not have two hearts—a heart for God, and a heart for sin.

God loves a broken heart, not a divided heart.

Thomas Watson