I don't believe the Universe has a cause. You seem to be confusing cause with reason (teleology) anyways. The Universe means everything in existence. I don't believe everything in existence is linked in a single causal chain, which is what the Universe having a cause would imply. Everything could have a purpose or not have a purpose without a cause, but I don't believe everything happens for a reason either. I don't even think it's logically sound to say existence as such has either a cause or a purpose. If you liked philosophers besides Thomas Aquinas including ones the Catholic Church supposedly likes such as Plato and Boethius you've had heard of the idea of God as being and evil as nothing. Supposedly Boethius is a Blessed even though many people have called him a pagan for his rather Jesus-less prison book. Thomas Aquinas comes within two inches of contradicting Christianity's own scriptures anyways since Elijah and Enoch were taken to Heaven (which, while not the final destination of souls, seems to preclude damnation) without dying first and the people who denied Jesus's miracles after having witnessed them seem to have been conclusively damned before they died.

You don't smoke books on modern logic, topology, and cosmology if you intend to read them, and I also don't think about you enough to be able to hate your guts.