To emphasize the spiritual danger his audience is in, Edwards often relies on imagery of a hungry hell or devouring devils, as seen in this passage:
The Devils watch them; they are ever by them, at their right hand; they stand waiting for them, like greedy hungry lions that see their prey, and expect to have it, but are for the present kept back; if God should withdraw his hand, by which they are restrained, they would in one moment fly upon their poor souls. The old serpent is gaping for them; hell opens its mouth wide to receive them; and if God should permit it, they would be hastily swallowed up and lost.
To be eaten by anything is unpleasant, let alone eaten by a lion or a serpent! There is no escaping a vicious predator that wishes to eat its prey, and here sinners are the prey that vicious animals will tear apart. This image of being eaten is visceral and contributes to the sense of imminent danger Edwards wants to create. Yet, in the midst of this terrifying imagery, Edwards characterizes God as merciful by his "restrain[ing]" of the devils, thereby urging sinners to repent and hasten to Christ without delay.
Also worth noting are the other literary devices Edwards uses to promote this imagery. Although it's not as impressive as his multi-paragraph spider simile, here Edwards writes that the devils which await sinners are "like greedy hungry lions." Likewise, "hell opens its mouth," a personification which allows Edwards to again call up the image of sinners being devoured.
It may seem obvious, and even in Edwards's time it was a common trope, but it is worth noting the fiery imagery Edwards uses to describe hell and God's wrath throughout the sermon, as in this sentence:
The wrath of God burns against them, their damnation don’t slumber, the pit is prepared, the fire is made ready, the furnace is now hot, ready to receive them, the flames do now rage and glow.
Repeatedly, Edwards describes hell as burning hot, and God's wrath is also often compared to fire. This is not a unique association, but it is a visceral image that further builds the audience's terror of hell. More so than today, fires would have been a part of everyday life for nearly everyone alive in this time period. Alongside fires used for cooking and warmth, Edwards's audience might have witnessed larger conflagrations that destroyed homes or whole towns; they might have even seen criminals, disobedient slaves, or accused witches burned at the stake. Edwards's fiery imagery, then, would have connected with the entire audience. Anyone who knew what it was like to be burned, or who had seen people and buildings destroyed by fire, would have then connected God's wrath to that physical feeling of pain they had witnessed or experienced. They would also associate God's wrath and hell with the striking visual of a fire, which Edwards personifies here by saying that the flames "rage."
Finally, note the alliteration Edwards (like many Puritan preachers) employs in the above quote. His list of the ways in which hell is ready to receive sinners is made punchier and more memorable by alliteration.