Southern Noachide, although this is a Jewish forum, about half our members are Christians. We've had Christian members here from the start. So if you're happy being a Noachide, then good for you. But I don't want to get into the the whole Judaism vs. Christianity debate here. We Jews, (including yours truly) believe in our religion. And the Christians believe in their religion. As long as they don't missionize, and they sincerely support Jews/Israel against the left, then they're welcome here. So there are some areas where we're going to have to agree to disagree.
Now getting back to why Jews don't aggressively defend the Torah and try to influence non Jews, you should know that Jews don't believe in prosletyzing. I think when Chaim uses the term "light unto the nations" he means Jews should lead by example, like in terms of how they live their own lives, and how they treat others.
In terms of "aggressively defending the Torah," I believe you alluded to this in one of your earlier posts.
On the one hand, us Jews are always accused of running the media, the world, the banks, etc. So if we were to somehow "aggressively defend the Torah," all we would probably hear would be "Shut up you dirty Jews! You killed our messiah! You already run the world..." blah blah blah.
The Catholic Church, like all the rest of Xianity (with the sole exception of the Judaeophilic and Biblicist Fundamentalist Xians) are headed inevitably into the garbage can of history. They teach that the Torah is mythology adapted from Babylonian and Canaanite paganism and deny that it is from Heaven. Is it any wonder that Xianity is so corrupt?
I only wish that Jews were public and aggressive in defending the Torah so that those Xian groups that have reverence for it would see that there is an alternative to Xianity. Why they are not (especially given the large Orthodox Jewish student populations at Bible-hating universities) is absolutely incomprehensible to me. Just imagine what moslem students would do if the academics dissected **their** "holy book."