The New Age concept of ascension - what is it?
The concept of ascension is central to New Age belief, so you'll hear New Agers talking about it a lot. So what is it?
New Agers essentially believe that it's humanity's destiny to undergo "spiritual evolution" to a next level of existence. At this point in time, the popular belief is that our DNA - or at least the DNA of those who "download" "DNA upgrades" from Source will "shift to 5D" in the near future.
Despite its name, "5D" has nothing to do with mathematical dimensions. Instead, New Agers believe that matter exists in varying states of density, and the fifth density is essentially more ethereal than "3D," or the third density, which we presently live in.
Ascension is functionally the Christian rapture with a eugenicist twist. Where Rapture-believing Christians believe that if you'll spontaneously be translated to spirit form if you convert to (the right kind of) Christianity, New Agers believe that you'll essentially be spontaneously translated to spirit form if you get close enough to God, or Source.
Some people believe that New Agers don't think they have to do any work to ascend - but this really isn't true. Most of them that I've seen believe that they have to "raise their vibrational frequency" so they can connect to Source energy and receive these "downloads." It's functionally the same idea that in order to go to Heaven, you have to get right with God.
So what are the problems?
First of all, it's spiritual eugenics. They effectively believe that people who practice their form of spirituality literally have superior genetics to those who don't. Many believe that it's just nature, fate, God's will, or whatever you want to call it, that those who don't or can't "upgrade" will essentially die off.
Because New Age doesn't have any central authority, beliefs surrounding this vary wildly, and there are relatively benign beliefs about what ascension will entail; EG, Earth will split into two timelines - one where the people who ascended get to live, and one where the people who didn't ascend get to keep reincarnating until they finally do get to ascend and join the other Earth.
Unfortunately, there are also those who believe that climate change is not a man-made phenomena, but rather is part of Earth's ascension process (they believe that Earth is going to ascend to 5D, too), and that related deaths are meant to purge the world of the unevolved.
Another concerning belief is that of "ascension symptoms," where symptoms that could potentially be very medically concerning are dismissed as a natural part of the ascension process. Couple this with a strong mistrust of actual medicine and real doctors (New Age is tied up in conspiracy theories of all kinds), and you've got a recipe for disaster.
One other thing the idea of ascension has in common with the Rapture is the number of times it's been supposed to happen, but failed to materialize. Lots of New Agers expected it to happen on December 21st, 2012. When it didn't, many rationalized it by saying that a consciousness shift had still taken place, and that this consciousness shift was important in preparing the world for actual ascension later on. Basically, it was pretty typical failed prophecy rationalization stuff.
New Agers continue to draw in people who are simply unaware of the movement's long, long history of failed predictions. The average person isn't going to go back and comb through 50+ years of New Age literature to see just how long they've been making extravagant predictions that just never manifest, let alone realize that all of these other failed predictions means the current predictions aren't all that likely to come true, either. If someone looks into it, there's a high chance they'll accept the rationalizations and believe that the predictions actually apply to their own near future, because "your generation is the special generation" is a powerful ego trap.
So yeah, in a nutshell, ascension is just the Rapture for people who believe in spiritual eugenics; and just like the regular Rapture, it has a long history of being involved in failed predictions.
