In reference to an earlier post (I don’t remember where) regarding the possibility of someone being a partner with the RBSO in Creation, the gemoro (Shabbos 119b) says that a Yid who says Vayechulu on Friday night becomes a partner etc. (It also says the same thing (10a) earlier about a dayan who judges correctly, but that statement is more exclusive.)
The point is, though, that although one can indeed become a partner with Hashem, it clearly doesn’t mean an equal partner or one with the same powers. After all, I imagine we all say Kiddush on Friday nights but none of us (I think and hope) consider ourselves on the level of a full partner.