Not too long ago I was reading Paul David Tripp's book Instruments in the Redeemer's Hands. I came across the following statement that show how our emotions can serve as "tip-offs" to idols in our lives. Tripp writes,
If we want to know what people really want, we have to learn about their emotional life. Happiness is the result of what my heart craves. Discouragement is the emotional response of my heart when the thing I live for moves farther away from me. My heart is filled with fear when I suddenly lose what I am convinced I need. In short, our emotions reflect what we worship.
This dovetails perfectly with the question the Psalmist put to himself: "Why are you cast down, O my soul, and why are you in turmoil within me?" (Psalm 42:5, 11). That question could also be rephrased when I am elated over something: "Why are you so happy, Matt? Why are you so cheerful inside?" My emotions serve as wonderful indicators of what I worship. Thus the more conscious I am of my disposition, the more I'll be able to readily define and to destroy (with the Lord's help) idols in my life.
Our dispositions serve as "warning signals" for us, enabling us to fight temptation at the heart level and not just the behavioral (or verbal) level. It helps us to get to the root of the problem rather than simply attacking the fruit of the problem.