chapotraphouse

BeanisBrain is conflating two things I believe. To "Immanentise the eschaton" refers to, essentially, taking actions to hasten the apocalypse. You are trying to bring about heaven by creating the conditions for judgement day. It is generally a pejorative term used to criticise various Christian sects. It can refer to any action taken to hasten judgement day. While it generally is applied to postmillennialism or similar groups it could equally apply to the Christians exporting red heifers to Israel for doomsday prophecy reasons.

Postmillenarians are people who think that Jesus through his sacrifice brought about the conditions that allow us to create the conditions necessary for heaven on earth, which would then "summon" Jesus, and that Christians have a responsibility to do so. Essentially they view it as their duty to make the world "better" by living according to the teachings of christ and that this will result in judgement which they believe most of us are gonna make it through just fine by virtue of us being nice enough for jesus to come back. This is generally where you get stuff like the social gospel and Christian abolitionists. So of course some conservative Christians fucking loathe it. And there you get the criticism of it as being immentising the eschaton, and that being a bad thing because they believe they've misunderstood the nature kf the millennium.

So as i understand it BeanisBrain is either accepting the criticism of a specific doctrine done by others who disagree with it as being universal Christian doctrine, or they have misunderstood what the term means.... or I'm wrong.

Edit: This post makes it seem like that 1: postmillennialism is inherently a good thing or that I approve. It isn't and I don't. Living according to Christian rules to bring about judgement day can also lend itself to a lot of harmful social doctrines. It depends on the individual church.

2:That other Christian groups that don't fall into this don't practise "utopianism". Early Mormons rid themselves of property ownership and many early Christians held all things in common.