This knowledge was obtained through a very painstaking, yet fascinating book I read a decade ago called My Big TOE (theory of everything) by Thomas Campbell.
Think of dimensions as fequency. Some resonate higher than other folks. The "normies" would be at the low end of the 3rd dimension of frequencies. Us critical thinkers would be nearer the top. Some people have the ability to access higher dimentions through learned practice such as meditation or rituals. Or drugs. The occult have been keeping this knowledge hidden for years. Nichola Tesla was a absolute master at this. By tapping into higher dimensions you can gain certain knowledge or insights from "aliens"
Aliens are simply beings/spirits or whatever that have surpassed the 3rd dimension. There are both good and evil spirits. The right way to access the good spirits is through natual means, raising your level of conciousness and meditation. The wrong way is through drugs and rituals, where you usually come into contact with the evil dooers.
Thomas Campbell did extensive research on this over many decades. He proved remote viewing through his process for example. It is truly an exhausting read because of the insane amount of information. I could only read maybe 10 pages a day in order to wrap my head around what I had just read..the book is around 900 pages, took me 9 months to read, and i typically can read a novel in a few days. Not for the feint of heart. However, Its the most fascinating thing Ive ever read, and seemed very plausable and accurate to my chimp brain. If you have questions feel free to ask.
Also he has screwtube videos if your interested.
Demon Haunted World also touches on this, then you start looking more into it you find theres whole religious groups thar believe "Aliens" is just the current term used. Past terms used for these beings are ghosts, demons, angels, fae, fairy, etc.
Excorcism has also been on the rise over the last several years as "elites" push for us all to leave religion as they communicate with the evil on the other side.
We need to keep or go back to faith to call back the good.
It isn't just some religious groups. There is a whole world of 'alt history' out there. I've spent years digging on that for my own reasons. I'm not religious but I have an interest in all of them also. The more I learn [from all over the world] I'd say "aliens" are indeed the ghosts, demons, angels etc of old. There are some pretty rad descriptions of "UFO's" in the Bible, just like the Sanskrit texts talk of Vimana like it was common to have all these people/beings getting around in flying craft. Old school India, according to the Rig-Veda, Yajur-Veda, Sama-Veda and Atharva-Veda seems more like Star Wars once you take a look. It is an eye opener.