“Take a look at your heart. Everything you see in it that might sadden God, remove. God wants to come to you. Listen to Christ your Lord: “My Father and I will come to him and make our home with him” (John 14:23). That is God’s promise. If I were to tell you I was coming to stay with you, you would clean your house.
Now it is God who wants to come into your heart. Do you not hasten to purify it? How could he dwell with avarice? …God has commanded you to clothe the naked. But avarice induces you to strip the one who is clothed…I am looking at your heart. What do you have in it? Have you filled your coffers but thrown away your conscience? …Purify your heart.”
Augustine of Hippo (354-430) in Sermons 261.4 (PL 38,1203-4) as recounted in “Passions Transfigured, Thoughts Transcended” in The Roots of Christian Mysticism by Olivier Clément, 2.4.