Do I join the minyan?

Peace to the rabbi.
I am an Orthodox religious person (at least sociologically). I am convinced of the existence of a philosophical God. However, I engage quite a bit in biblical criticism, and tend to doubt very much that the source of the five books of the Torah is divine (I am completely willing to accept the Sage interpretation, at least as a conclusion of adopting its axioms), or that there was prophecy in the past (at least in the accepted sense). However, I am committed to the law (practically, not in terms of an obligation that falls on me). You have written more than once that those who do not believe in God have no value for their mitzvot. You gave an amusing example of a person who put on tefillin at a Chabad stand and later that day repented, saying that he must put on tefillin, because the mitzvah that existed before his apostasy has no value.
If I do not believe in the Torah from heaven (certainly not in its entirety, and perhaps not even in part), do I join the minyan? If not, and there are ten of us praying together, should I withdraw from them/tell them that I am not joining the minyan?