Do you say that Jews are not engaged in a false religion from a Christian viewpoint? Or are you asserting the Jewish viewpoint? From a Christian viewpoint, the Jewish religion, as practiced, is false. You cannot expect a Christian pastor to preach from other than a Christian viewpoint - if he does, he is wrong.
Christian theology asserts that Christ is the Messiah.
Christian theology asserts that the Old Testament points to the birth, life, death and resurrection of Christ as Savior and Messiah.
Jews reject the foundational belief of Christianity as false - and continue to worship God as if the Messiah has not yet come.
If my religion says Christ is the Messiah, the risen Lord and your religion says He is not, then at least one of them is wrong, or false.
I thought we were supposed to be “incomplete” not false.
Judaism is the truth. Christianity is the truth fulfilled. Sadly, most Jews deny Christ as their Messiah. They have not recognized the completion, fulfillment, of the Old Testament.
I am not an expert, by any means, but that’s how I see it. When I read the Old Testament, I don’t consider it a “false” religion, as I would, for example, a Qoran. I consider it the old covenant - but still the word of God.