Without a verified “contact,” there’s no way to know either way. Secular evolutionists use the premise that given enough time, life, and eventually intelligent life, will emerge spontaneously from inanimate chaos, an unproven theory at best. But theists may also contend that God created intelligent (corporeal) life elsewhere and simply didn’t bother to tell us about it. This is also an unproven theory. So I guess that makes me a solid agnostic with respect to whether we are “alone,” as you have used the term. Of course, with God being everywhere the highest possible form of intelligent life, in the ultimate sense, we are not alone, and never will be.
That is a SELF EVIDENT TRUTH. The question at hand is how much time. Perhaps evolution requires a trillion trillion years and god created life. Or maybe it takes a billion or so and evolution is true.
But it is self evident that from the chaos and given a nearly infinite or nearly infinite of time, life will certainly arise.