I don't know who you are, George, but you can't teach your grandmother to suck eggs. I have had extensive and very deep friendships with religiously observant Jews all my life. (Including with my husband's Reform rabbi and his wife, herself a formidable Jewish scholar.)

While some Jews are justifiably proud of the tenacity and strength of their culture, that does not equal believing that God revealed himself only to the Jews, or that people outside Judaism are cut off from God. That is by no means part of mainstream Jewish belief. Quite the opposite is true.