Jonah 2:8

Thought of the moment while I wait for some water to boil:

Those that observe lying vanities forsake their own mercies.

--Jonah 2:8 (KJV)

Those mercies that I ought to have and live in, which would be my strength and sustenance, are lost because I do not keep my thoughts pure and true. The NIV translates "vanities" as idols, but the sense need not be so restrictive - insofar as I put my trust and hope in any being (including myself), idea, or thing other than God, and insofar as I take actions other than in accordance with His commands, I remove the very mercies by which I am intended to live.