(Never said there was...anymore than I would contend that "there's no difference between Christian denominational theologies" ... Calvinists, for example, stress more the sovereignty of God than an Arminian)
Now am I saying Judaism is "just another" Christian denom? (No) Am I saying that some Jews worship the same God Christians do? (Yes)
You seem to get hung up on the phrase "the study of" (theology)
Lots of illiterates thru the centuries have worshipped THE TRUE and LIVING GOD without having a fine-tuned "theOLOGY"...Lots of pre-schoolers and early primary kids have worshipped THE True and Living God without having a fine-tuned "theOLOGY"...
Can a Jewish candidate know this God enough to worship Him? (Yes) Can a Jewish candidate know this God enough to live with Him forever minus trusting the Messiah? (John 14:6; 17:3 seem to cast doubt on that)
You're not saying that Jewish candidates -- upon praying/appealing to God for relief, help, aid, etc... -- are calling upon a false god, are you?
In fact, let me emphasize that question again -- and then encourage you to answer that question
>>”Am I saying that some Jews worship the same God Christians do? (Yes)”
Which ones? The Christian ones?
:)