If you thought the Behemoth of chapter 40 was impressive, just wait 'til you hear about the Leviathan of chapter 41!
For 34 verses, God describes one of the pinnacles of His creation - namely this scaly, surly, awesome beast called Leviathan. Nobody really knows who or what the Leviathan is, but there have been plenty of guesses! He sounds like a reptile, perhaps a crocodile or dinosaur? Even though this is poetry and license must be granted, there are also passages where he sounds more like a dragon or even the Dragon himself of Revelation!
I believe that God's point is that if we have no mastery over one of His creatures like the Leviathan, we must understand that we have no mastery over God Himself either. In our pride, this can be a difficult lesson for human beings to learn. Nobody likes to be told that there is something that they can't do. But when it comes to having all the mysteries of the universe unlocked and all its secrets disclosed, we must admit that these things are far beyond anything we can understand or even imagine.
The One who made the Leviathan is certainly more powerful and awesome than us!