I can be sure He has done this, because I do not perceive I am God; a perception that either must be true, or a mistake, or a willfully intransigent self-delusion. God, however, would not be willfully intransigent with respect to Himself–that would be the end of Himself and all reality. And He would not intentionally delude Himself, for much the same reason. The Son, in other words, would not rebel against the Father; and the Father would never at bottom (or as ‘the bottom’ or ‘ground’ or ‘foundation’ of all reality, including the Deity’s own reality) disown the Son.
Thus, one way or another, if reality must be presumed (literally ‘for purposes of argument’) to be consistent, and if God is the ultimate reality, then I cannot be God. I would either know that I am God, or at worst God would never let me consider the question and reach a wrong answer.
Taken altogether, I find I myself am my own strongest evidence that God exists and has created, not only begotten.
The first thing God creates (not self-begetting) must be something which, as ‘itself’, is reactive and not active–for action (specifically self-generation) is the most primary and basic attribute of God upon which He Himself and all else is ‘based’; and His first creation must be fundamentally distinctive in characteristic from Himself, else He would not be creating. A reactive Nature of some sort is therefore a necessary component of a reality that includes not-God (i.e. created) entities. If God creates, at least one ‘Nature’ must exist, and it must be (considered as itself) reactive.
Thus God limits Himself within His infinite particularity.
[Footnote: An infinite particularity, by the way, does not mean that mutually exclusive facts will be true about it or within it. I only mean that God, as an actual entity, is one positively real thing–the Most Real Thing–with a particular character that can be at least partly defined.
I know theologians, including Christian ones, have often claimed that God is undefinable–but even that claim is itself a defining characteristic. Plus, the same theologians who say this, usually have no reluctance about going on to say God exists, is just, is loving, is the Creator etc.: they provide a list of particular characteristics, and often quite a long list, which they expect to be accepted. When (to avoid such lists of particularity) they resort to negative theology (or to an unrestricted positive theology), they end up saying nothing at all about God. I consider this to be a well-meant but deadly addiction to the pleasure of contradiction.
Theology should go somewhere–to God, for God, about God. Even an atheology goes [u]somewhere, away from God; and so, to that extent, may respect God more than a so-called theology that goes nowhere in regard to God!
Put another way: some theologies prefer the equivalent of an autoerotic fantasy–even if the fantasy has ‘God’ for the subject. I say rather it is better to be the spouse of a true Husband.]