"The wrath of God is like great waters" metaphorically depicts God's anger towards humans as rising higher, much as water held back by a damn does. Nothing humans are doing lessens God's fury at them. In fact, they keep sinning, which, like water rising against a dam, builds the pressure higher and higher. At any moment, God's anger, like water bursting in a mighty torrent over the dam, could break out and crush the sinners.

So far, the dam, which is God's hand, is holding back the flood, but at any moment He could withdraw His hand. Then, the immensely powerful waters of his fury would flow forth, and even if humans were ten thousand times more powerful than they are or ten thousand times stronger than the "sturdiest . . . Devil in Hell," they would be destroyed by God's wrath.

The image helps readers visualize how angry God is at them and how much more powerful He is. It emphasizes human vulnerability and helps undermine the notion that humans have power or agency. It reinforces Edwards's point that humans have no choice, if they wish to be saved from hell, but to humbly bow down to God and accept Christ as their savior. The image also emphasizes the precariousness of the human condition—at any moment, God could unleash his fury. This means that the time to repent is now.