The idea of God always existing

[Phil]

If reality was not caused, then it has either always existed (which is not possible because we should then be in a state of heat death already), or it came from nothing (which assumes that nothing is something, which it's not).

You don't read much on cosmology and you make that painfully obvious with your heat death already claim.

As to your nothing claim, define nothing and then give me an example. There is always entropy (Joules per Kelvin) and the cosmological constant (vacuum energy) even in de Sitter space. You have a de Sitter space with either a positive vacuum energy (with negative pressure) or negative energy density (positive pressure). Those are respectively de Sitter space and anti de Sitter space.

Do us a favor. Shove your idiotic Christian non scientific bullshit deep up your ass and preferably you should perforate your colon at the same time.

---

and we don't know how a universe (or multiverse) can just exist.

There is no concrete scientific explanation but there are a few scientific hypothesis that are very promising. God is just a way to avoid the question and a way for the theist to feel that humans are special in the universe.