An analogy is a figure of speech in which there is a likeness in one or more ways between things otherwise unlike. A good example of analogy being used in scripture can be found in chapter 8 of the book of Isaiah:
Because this people has rejected the gently flowing waters of Shiloah, . . . therefore the Lord is about to bring against them the mighty floodwaters of the River — the king of Assyria with all his pomp. It will overflow all its channels, run over all its banks and sweep on into Judah, swirling over it, passing through it and reaching up to the neck. (Isaiah 8:6-8)
In this analogy, the devastation of Judah caused by the invasion of the king of Assyria is likened to the devastation caused by the power of a flood which destroys everything in its path. It is important for us to recognize that this is not a literal flood, but that the imagery of a flood is being used to describe the effects of the invasion. The writer of this passage clearly intended it to be interpreted as an analogy because he explicitly stated that the floodwaters of the river represents the king of Assyria.
In properly interpreting an analogy used in scripture, we must be careful not to assign more meaning to the comparison than was actually intended by the author. In the above passage, for example, we would be taking the analogy beyond what was intended if we claimed that the ground would be muddy after the invasion as it would be after a literal flood. No such meaning is intended.
The Bible is rich its use of analogies and we should, therefore, be prepared to properly interpret them.