Lack of belief in Jewish theology isn't a major problem in Judaism.
I think I might have phrased this a bit differently. But, like a lot of the things you mention here, it's tricky. The traditional answer to the question "Am I a good Jew if I follow the mitzvot[1] but don't believe in G-d" would be, in my opinion, "Of course, why are you wasting my time with such foolish questions?" On the other hand, the answer to the question "Am I a good Jew if I believe in [Jesus/Mohammed]" would be, in my opinion, "Of course not, why are you wasting my time with such foolish questions?" So I don't know how I'd boil that down...
There's a poem/prayer/song, Yigdal, which is sometimes sung on Friday nights at the end of services, which is sort of a credo. It's a list of things Jews believe in. Must be pretty ancient, right? Nah. It's modern (relatively speaking -- attributed to Rambam, who lived around 1200; the poem is dated to around 1400. Even 1200 is pretty new!) And on that list, there are things that some branches of Judiasm don't believe in.
[1] Mitzvot: Commandments, but with a side of "laws" and a helping of "good deeds". Stuff you're supposed to do (and not do).
no subject
I think I might have phrased this a bit differently. But, like a lot of the things you mention here, it's tricky. The traditional answer to the question "Am I a good Jew if I follow the mitzvot[1] but don't believe in G-d" would be, in my opinion, "Of course, why are you wasting my time with such foolish questions?" On the other hand, the answer to the question "Am I a good Jew if I believe in [Jesus/Mohammed]" would be, in my opinion, "Of course not, why are you wasting my time with such foolish questions?" So I don't know how I'd boil that down...
There's a poem/prayer/song, Yigdal, which is sometimes sung on Friday nights at the end of services, which is sort of a credo. It's a list of things Jews believe in. Must be pretty ancient, right? Nah. It's modern (relatively speaking -- attributed to Rambam, who lived around 1200; the poem is dated to around 1400. Even 1200 is pretty new!) And on that list, there are things that some branches of Judiasm don't believe in.
[1] Mitzvot: Commandments, but with a side of "laws" and a helping of "good deeds". Stuff you're supposed to do (and not do).