Whether as a whole or separately all things are contingent that is it is equally possible for something to come into existence or not. Also it is possible for any thing to come into existence at any time in any place and in any form and with any character.
We see that nothing or no-one in the world whether conscious or unconscious living or non-living has any role to determine the way and the date and place of its coming into existence and its character and features. So there must be some power that chooses between the existence and non-existence of any particular thing and gives it its distinguishing individual characteristics. This power must be infinite have absolute will and all-comprehensive knowledge. Necessarily this power is God.