Yes. Compare, on the other hand, Aristotle, for whom a thing is nothing without it being that thing. To ask for the origin of that thing is superfluous. Why? The thing is--exists--of its own accord and, as such, exists necessarily and is eternal. The character of this thing has the properties of divinity.
Alamo-Girl has given very readable and informative reply illustrating this necessity with regard to a geometry (not existence). But the reasoning is similar.