The Practice of the Presence of God is a book of conversations and letters from Brother Lawrence a 17th Century monk who devoted his life to seeking God. He said "I know that for the right practice of it, the heart must be empty of all other things; because God will possess the heart alone; and as He cannot possess it alone without emptying it of all besides, so neither can He act there, and do in it what He pleases, unless it be left vacant to Him.