Or, you know, an higher and/or omnipotent entity. At some point along the causal chain, there is no "testing" - you are forced to resort to metaphysical reasoning.
This doesn't actually solve the original problem. Either something was always there or something can come from nothing, and both of those seem to violate causality as we understand it. Saying "God was always there" isn't really that different from "The universe was always there" when it comes to resolving the violation of causality.
Sure, you can invent any explanation that you like. It just isn't more convincing than "the universe (or an outer universe giving birth to this one) was always there", since they solve exactly the same problem.