“A foolish consistency is the hobgoblin of small minds.” (Emerson)
Not every consistency is foolish. But then, neither is every inconsistency smart. Consistency is sometimes hard to find. This is especially true when it comes to politics and doctrine. These disciplines (or lack thereof) are so riddled with emotion that consistency is nearly impossible. The only hope is to be as consistent as possible. In doctrine, the only way to do that is by careful consideration of the Bible.
Today when anyone proposes that a particular doctrine is inconsistent with the scriptures, it is often countered with, “That’s just your interpretation.” To be fair, sometimes it is. And if it is “just” your interpretation, then it probably doesn’t matter much. But if that interpretation is supported by some biblical scholars it may have more weight. (Although to be honest, some of the worst interpretations of scripture are held by large numbers of scholars.) If it is supported directly by scripture, then it is really no longer interpretation.
As an example, some people oppose, or at least do not support, the idea that the devil is a fallen angel. Those that say he is often base their doctrine primarily on Isiah 14:12-15 and the mention of Lucifer.
How art thou fallen from heaven, O Lucifer, son of the morning! how art thou cut down to the ground, which didst weaken the nations! For thou hast said in thine heart, I will ascend into heaven, I will exalt my throne above the stars of God: I will sit also upon the mount of the congregation, in the sides of the north: I will ascend above the heights of the clouds; I will be like the most High. Yet thou shalt be brought down to hell, to the sides of the pit.
Interestingly, they say this must be about the devil because it calls him Lucifer, and Lucifer is a name for the devil. How do they know Lucifer is a name for the devil? Because this passage uses the name and it is about the devil. That is known as circular reasoning. Fortunately, many translations newer than the King James Version translate the word rather than making it a name.
If you challenge these people, they use a variant on the “that’s your interpretation” argument. But when you point out that verse 4 says it is about the king of Babylon, and verse 16 says it is about a man, they respond that it is symbolic language. And there is where the inconsistency comes in. This passage, that clearly states to whom it is addressed, must be figurative, but other passages that appear figurative must be taken literally. A reign of “a thousand years” must be literal, even though it is in the middle of an obviously figurative passage (bottomless pit, devil as a dragon). If the passage in the Revelation is a literally specific thousand years (no more, no less), then why is a passage that is more literal necessarily figurative. Only because it fits a specific doctrine, emotionally held.
Eventually, the response is to stop listening. “The Bible is the true word of God, so stop trying to change it.” (An interesting response from one trying to change what the Bible clearly says.) “I’m not going to argue with you about this.” (Because you know you are losing the argument, but that’s fine because we are getting nowhere.)
The problem with much interpretation of prophecy is that the holder of a doctrine is not consistent in how they interpret prophecy. Sometimes to counteract that inconsistency one needs to look at what the scripture specifically says. Then it is no longer interpretation.