I always feel like theists don't understand the 2nd law of Thermodynamics. It basically says that in a "closed" system, potential energy will equalize losing it's ability to do work. This universe is apparently a "closed" system in that new energy is not being added and the universe is losing its potential to do work. Lookup "heatdeath" for our universe. We know the universe is not eternal, but the Cosmos (all that is) certainly is eternal because energy is eternal since it cannot be created, nor destroyed. Since energy cannot be created, it means it is "uncaused", as well as there can be no Creators since it cannot be created. If our universe was an "open" system, then that means outside energy is being added to maintain potential to do work. We have no idea if our universe will remain a closed system or if at some point it will open up for additional energy. You can look up why Craig's arguments fail.