It most certainly is. One cannot truly "prove" anything, since all such "proofs" are apprehended solely via the senses — a subjective process. The senses can be fooled; the result, as Descartes famously observed, is that is it impossible to say definitively that anything is true based upon the evidence of the senses alone. The only thing one can be certain of is one's own existence, i.e. that which is experienced directly, without recourse to the senses: cogito, ergo sum.
Logically speaking, there is more support for the idea that God exists than the contention that elfman2 exists. After all, the existence of a non-contingent being (i.e. God) is logically required if a demonstrably contingent universe is held to exist. The existence of the universe, however, in no way depends of the existence of elfman2.
The logic is inescapable: since the only thing one can know for sure is that oneself exists, then all that one holds to be true outside of that fact is held to be true on the basis of belief. The existence of atoms, other people, France, God — all must, in the final analysis, be taken on faith. Therefore, one must either be a solipsist or a believer; there can be no other option.
I believe that you exist, for example — but I can't prove it, and neither can you. Like one's own existence, the existence of God needs no proof — both may be inferred from the evidence of the senses, but in the end both may be known only by direct experience.
That’s about as true as saying that a point in space is always an approximation. In a mathematical context, yes, the definition of a point is always subject to greater precision. In the context of describing the location of objects (as well as the degree that a claim is “proven”) does not depend on an infinitesimally small measurements.
I can prove that a hungry tiger is dangerous. But because I can not provide evidence that sustains itself to 10 to the millionth, billionth or trillionth power does not make my judgment that danger exists a “subjective” one. One does not have to thrash in the inability to disprove the one in a trillion-trillion chance that everyone’s eyes are consistently lying to them in order to pronounce something proven.
In this context of human life, it’s provable by overwhelming evidence that tigers are dangerous. Our experiences are similar enough to call that an “objective” claim. But as far as I know, there is no similar overwhelming evidence that “proves” the validity of the Bible.
Of course if you want to preface your claims of proof being subjective as assuming that the most infinitesimally small amount of doubts precludes objectivity, then I won’t argue that it’s true in that narrow mathematical context, removed from the human experience.