Everything that begins to exist has a cause.The universe began to exist. Therefore the universe has a cause.
Why couldn't natural forces have produced the universe? Because there was no nature and there were no natural forces ontologically prior to the Big Bang—nature itself was created at the Big Bang. That means the cause of the universe must be something beyond nature—something we would call supernatural. It also means that the supernatural cause of the universe must at least be:
•spaceless because it created space
•timeless because it created time
•immaterial because it created matter
•powerful because it created out of nothing
•intelligent because the creation event and the universe was precisely designed
•personal because it made a choice to convert a state of nothing into something (impersonal forces dont make choices).
Turek & Geisler. I Don't Have Enough Faith To Be An Atheist. CrosswayBooks; 2004.
Thanks to Dr. Frank Turek, Dr. William Lane Craig, RC Sproul, as well as Dr. Henry F. Schaefer III