We are all too familiar with the same old human pitfall: we rush after the desires of our hearts and worship ourselves instead of Jesus Christ. And yet, the dangers of inward idolatry are a neglected topic in Western theology. Without God's First-Commandment-focused Law, we would never truly know the depth of our spiritual disease. Anything we fear, love, or trust more than the true God is, plain and simple, our god. Drawing upon Martin Luther's key insights on the theology of idolatry, The Unholy Trinity unmasks contemporary idol worship and its futility. Luther's unparalleled ability to get to the heart of human sin helps us see through the lie of self-sufficiency. Only when walls of man-made security are broken down can we hear the Gospel as good news-by grace, God gives us every good thing we vainly try to provide for ourselves.