“The error of rabbinic Judaism “ and “validate” are two stumbling blocks in your comment. First, whatever error you have in mind ( and there could be many, for Jews do not have an infallibility doctrine). ... Does not matter. They are praying to the same God of Abraham, Isaac , and Jacob as Catholics do (albeit with distinctives in both traditions). This is a far cry from inviting some sort of pagan into church. And for what it’s worth, there is not one significant moral teaching in The New Testament that did not already have precedent or does not have a parallel teaching in Judaism. Judaism is , if you will, a special case for the church because Christianity is a special type of Judaism, however that can be best phrased.
Rabbi Jesus taught from the Jewish scriptures and as you know he said that not one dot or tittle was wrong. Jesus also instructed his followers to respect or follow the preachings or rulings of the other rabbis (even while criticizing some of them for not living up to the standards they taught and even though those rabbis did not accept any divinity claims for persons including of course Jesus). They sat on the seat of Moses , Jesus recognized the authority of their teachings regardless of the other issues. Second point about your note. It does not necessarily “ validate” a guest’s positions or beliefs to extend him hospitality (and as before, a shared prayer is confidently something God will still receive and hear. Especially as Jesus prayed to the same father God that the rabbis do ). Since there is only one true god and since both the church and synagogue pray to Him, there is no chance of any other supposed god getting mixed into a shared prayer. Well, anyway I appreciate your view and hope you will mine. Blessings and thanks.
It would be fine to confer with the Jews (every time I use the word as a reference to religion, not ethnicity) in a way that does not include worship, for we do not worship the same. Like I reminded the reader several times, we pray to the Crucifix as the image of God. They don't. Communal worship is thereby impossible; however, if it is watered down to the point that there is no Crucifix, then that is the validation of the precise error of modern (past 2000 years) Judaism.
Very nearly the same applies to the communal worship with the Protestants, as comments coming from them on this thread amply prove.
Both groups should be invited to the Catholic proper worship, which is the Holy Mass, but the intention should be evangelism and not common prayer before there is a conversion.