King Nebuchadnezzar exalted himself above God. This is normal human behavior. Sinful men stand in judgment over God and question His decrees. They imagine themselves to be cleverer than God, thinking that they can outwit Him by sinning and then repenting at the last minute. Though they can see, they presume that He is blind to their sin. They slur His character by thinking that He will tolerate their hypocrisy. Like the arrogant king of Babylon, they think that God lacks even the power to deliver from their mighty hands.
Daniel 3:15 Now if you are ready at the time you hear the sound of the horn, flute, harp, lyre, and psaltery, in symphony with all kinds of music, and you fall down and worship the image which I have made, good! But if you do not worship, you shall be cast immediately into the midst of a burning fiery furnace. And who is the god who will deliver you from my hands?