A Tale of Two Entities*
Because it is possible for the entire universe to cease to exist, its existence must be radically contingent. Even if the universe has always existed and was uncaused (i.e., the view of steady-state cosmology), its existence would still require a causal agent to keep it from ceasing to exist, to prevent its exnihilation. Since no natural cause exnihilates anything, the cause must be supernatural. A supernatural being (one that is itself uncaused) is required to prevent the universe from turning into nothingness.In other words, even though everything that we know about universe tells us that it will not simply cease to exist, nevertheless, the universe could simply cease to exist. Ergo, there must be a supernatural being who cannot cease to exist who keeps the universe from ceasing to exist.
Call me crazy, but I'm not 100% sold on this yet.
* Original title changed to something more neutral with respect to the discussion.