A property of countable infinite sets tells us that there must be a beginning.
Just as a woman cannot give birth to herself, so nature could not have brought itself into existence. The cause of nature, therefore, must be not-natural.
Why a nature explanation is logically impossible.
In order to bring time into existence, God must be timeless. It is logically impossible for a timeless entity to have a beginning, therefore, it cannot have been caused by yet something else.
There are some significant problems with the idea that the universe was brought into existence by absolutely nothing at all.