There are two answers to the problem of its existence: the juvenile "Who cares? Maybe it was just kind of always there" and "Some force or entity capable of bringing it into being brought it into being."
Acknowledging God's existence is the only rational response to the universe.
At the end of the book of Job God basically says behold my creation and believe in me so God uses the cosmological argument.
I've always had a problem with the 'Big Bang' theory, in that, in order for the Universe to be created that way, SOMETHING VERY BIG had to exist to begin with.
The theory has never explained how a large body 'appeared in the heavens' and exploded to create the universe.
What created that body?
AMEN - Romans 1:20