Unbelief as sin justifies God’s judgment because it is an affront to Him. Unbelief goes about as if He weren’t trustworthy, as if His demonstrations were insufficient, and as if His commands were optional. Not only does unbelief deserve God’s wrath, unbelief also damages our witness and worship.
Unbelief torpedos our courage to witness. If I don’t believe that eating fruits and vegetables will help me be healthy, then I won’t eat them and I’m likely to be silent about their benefits in conversation. Worse, if I don’t believe that in Christ is life and that abiding in Him produces fruit, I will not be fruitful or faithful to call others to Christ. Unbelief blows a hole in the boldness tank and we will not acknowledge Him before men (Matthew 10:32-33) if our faith is empty.
Unbelief also bankrupts our convictions for worship. I will not praise what I do not prize, and I will not prize something I’m suspicious about. I will have no confidence to sing if I’m uncertain of His ability to come through or unsure that He is who He says He is. Doubt siphons off our confidence for worship until our faith is belly up.
“Without faith it is impossible to please Him, for whoever would draw near to God must believe that He exists and that He rewards those who seek Him” (Hebrews 11:6). We sin when we do not believe, we cannot please Him without faith, and our unbelief cuts off our courage and convictions. Disbelief isn’t something to play with, it’s something to confess as sin.