I confess I don't see a skeptical problem here.
It's true that any perspective I could occupy, no matter how broad, will be my perspective when I occupy it. But that truth is just a tautology: it's implied by everything, including by theism as much as by naturalism. It makes no difference to either of those positions.
Importantly, it doesn't imply that I can't achieve objective knowledge. From my perspective, elephants are bigger than mice: I perceive them that way. The fact that I perceive things that way doesn't imply that elephants aren't objectively bigger than mice, i.e., bigger than mice regardless of anyone's perception of them. Nor does it imply that I can't know that they're objectively bigger. To the objection, "But how can you know that you know this about elephants and mice?" one can reply with one's favorite theory of knowledge, which will explain how one knows anything, including how one knows that one knows that elephants are bigger than mice.
In short, I don't see how the inescapability of perspective implies the impossibility of objective knowledge, i.e., knowledge of facts that are facts independently of one's perspective.