Pertaining to eschatology, another reason eschatology is so important is that one cannot understand the individual pieces of the puzzle unless first has a template by which to read the individual puzzle piece. It is the box that has the whole on it that allows us to understand the many parts in the box we will be putting together.
In the same way we will understand no historical incidents (the individual puzzle pieces) correctly unless we have a proper eschatology that gives us a template by which to read the individual pieces (the box top picture that is needed to know about the puzzle pieces).
People (Christians) who have wildly varying eschatologies are trying to use the pieces from the same puzzle to make wildly varying realities — and all in the name of the same Christ. So, at the end of the day their respective eschatologies are giving them very very different Christianities — indeed one is tempted to say different faiths.
As Christians we can not lean into life at all properly without a right eschatology. “Christians” who have a wrong eschatology are, more often than not, at cross purposes from those with a correct eschatology (post-millennialism) and so are pouring water on each other’s fire. To be perfectly candid I don’t want amillennialism or dispensationalism or premillennialism or full Preterism to succeed or grow because those eschatologies detract from God’s glory and end up creating a finished puzzle that does not correspond to God’s reality. I suspect if those other eschatological schools were honest they would likewise admit that they do not desire my eschatology/theology to succeed for the same reasons.
The thing is that a person runs all their theology through their eschatology so that eschatology is before all considerations and not after. One does not do all their theology and say, “therefore my eschatology.” One does all their eschatology ands says “therefore the rest of my theology.” As such eschatology is both prolegomena and last things at the same time.
Our eschatology tells us how the Bible holds together and the way we understand how the Bible holds together tells how we understand all reality holds together. When you tell me a person’s eschatology, you tell me not only what kind of Christian I can expect to be working with but you also tell me what kind of human being I can expect to be working with.
In the beginning was the eschatology, and the eschatology was with God and the eschatology was God. This is so because God had the end in mind when He began the beginning and so everything He began He put the end of the matter in that beginning so that the end that he planned from the beginning would have a beginning that would end at the end planned from the beginning.
Eschatology is everything.
Get your eschatology wrong and all else will suffer. Get your eschatology right and all else will fall into place.