I'm not a believer, but I would assume that God is not outside (or inside, or in any location. As an absolute, this consideration feels like not applying to God. Hence can you define your relationship to God in a way that separate both from each others. Even the term "both" feels strange, as God is suppose to be everything and more.
Coming from that, the idea of the acceptance from God is a concept you have in yourself.
Maybe I got this wrong, intellectualizing spirituality is usually a terrible way to share about it.
If I can add some clarity, I think you inadvertently (1) blended Christianity with a kind of pantheism, and (2) took "outside" to only mean "not spatially colocated".
1. In Christianity, God is "present" everywhere only in the sense that there is no possible circumstance in which God would fail to have complete knowledge and power to act. We (Christians) do not believe that God is a sort of ether, like the Force in Star Wars, that contains or flows through everything.
2. Christianity teaches that God is not a material being, so you're correct in saying that God is not "inside, or in any location", because this would be category error, analogous to "what does the color yellow taste like?". Nevertheless, God is "external" to me in the ontological sense: "I am not (a part of) God". This is analogous to saying "my love for fast cars is 'outside' my love for ice cream". If this and (1) were not the case, absurdities would result, like tall people having more God in them than short people.
Given the above, I think projo is correct. My self-esteem is grounded in knowing that God -- a maximally great being -- created me, and loves me enough to submit himself to poverty, hunger, humiliation, and crucifixion on a Roman cross to fix what I broke. To those who "get it", this produces love, humility, and a sense of self-worth.
I think religions can lead to self-esteem in the way you're suggesting, though they may not provide a clear path to it, since many people don't "get it" even though they practice the religion. Religions also tend to require faith in a whole lot of things, which I think gets harder to do as the number of things to believe in grows.
That's why I'm working on a sort of abstract framework of being that includes a religion with a minimal number of prescribed things to believe in with a goal of self-development. Cultivating love, humility, self-esteem, etc. are all decoupled within the framework/religion to allow people to pick & choose only the parts they need.
When people are asked "what would God do in this situation" the place in the brain that lights up is the same as the "what would -I- do in this situation" region, so I think it's no different than before. Self-esteem is still self. It's just that in the monotheistic/polytheistic (not pantheistic) perspective, it could be considered external, although the mechanics are actually subconsciously internal.
Do you have a citation for that first claim? It fits my prejudices so neatly that I'd like to see the proof. I've tried to google a little for it with no success, so my apologies for any imposition.
Haven't read it & it's 8 years old, but here's this. Hopefully it'll point you toward better search terms. I used "what would jesus do brain imaging" without quotes.
Coming from that, the idea of the acceptance from God is a concept you have in yourself.
Maybe I got this wrong, intellectualizing spirituality is usually a terrible way to share about it.