Where Did the Essence God Is Composed of Come From?

Questions about where the essence God is composed of came from, whether God has the same choices other beings have and could choose not to exist, and how to convince a non-believer God matters if he’s undetectable and a non-interventionist.

 

• If things have to have a beginning, and God is something and not nothing, then where did the essence he is composed of come from? Can something create itself?
• Does God have the same choices other beings have, and could he could choose not to be, like other beings can, or is he somehow outside of being and non-being, thus not being a being at all?
• If God is undetectable and a non-interventionist, then how do I convince a non-believer he matters? Does he only matter because of the afterlife?