ONE of my favorite hymns as a young boy growing up in the Lutheran Church was “Onward, Christian Soldiers.” Others must have liked it as well, for I remember singing it frequently both in worship services and in Sunday school.  Over the years, however, those occasions steadily declined. It is now so long since I have had the chance to sing it that I assumed, until I looked it up the other clay, that it had been dropped from current Lutheran hymnals. It’s still there, it turns out, but it might as well not be: “Onward, Christian Soldiers” is today, in effect, a nonhymn.