How can you know something is infinitely powerful or that it will last forever (ie. an infinite amount of time)? Just because it is very very powerful or has lasted a very very long time, doesn’t mean it is infinite in those dimensions. Similarly, just because something has been around for a very very long time or just because you can’t remember something beginning, doesn’t mean it was never born. Maybe it is very very old, but you have no way of knowing if it was infinitely old.
If you think something is infinite in some way, then I would say that’s a belief. Infinity is a concept, and we have no way of knowing if anything infinite actually exists at all.
This is an except from a larger article: Can you know something is infinite, limitless, indestructible, eternal or unborn?