More on idolatry

Martin Luther on idolatry (from Luther's Large Catechism):

A god is that to which we look for all good and in which we find refuge in every time of need. To have a god is nothing less than to trust and believe him with our whole heart. As I have often said, the trust and faith of the heart alone make both God and an idol...That to which your heart clings and entrusts itself is, I say, really your God.