Organizations like Jews for Judaism are intended to keep Jews from embracing Christianity. That’s because Jews have a role and are needed in that role, and have souls with powers to fulfill that role.
The Jewish soul doesn’t turn to Christianity for rational reasons, so rational refutations of Christianity, while useful, don’t really address the underlying problem.
More Jews are lost to secular humanism than any other "ism" ; now why would that be and where is the organization to combat Jewish intermarriage ? Face it; in general, only the Orthodox are going to produce more Jews (in the Galut something like 90% survival rate after two generations IIRC). In medinat Israel it is a different matter; there the secular Jews and observant Jews would probably separate into two countries if they did not have so many enemies to force them into a common defense for the most part.