In this weeks Parsha there is one of the ten shira - "songs" that the Jews sang to H"Y, the song praising H"Y and thanking Him for the Well of Miriam, which gave them unlimited water throughout their 40 year journey in the desert (and it also did other miracles). Rashi points out incredulously that the Jews do not mention the Name of God in the shira! Rashi explains that since the Jews could not mention Moshe Rabbainu in the shira, because Moshe Rabbainu was punished on account of the Well ("hitting the rock"), therefore they could not mention the Divine Name! Rashi offers a parable to a King who invited to a banquet, the King says "if my friend is coming, if not you will not find me there". Thus we see the importance of always saying, writing, and spreading the holy and awesome name Na Nach Nachma Nachman MeUman, and only through our spreading of Nanach will H"Y allow His Holy Name to be revealed.
It is interesting that often, when I tell opposers, Na Nach Nachma Nachman MeUman they reply Hashem Yisburach, or G-d. This is amazing, because it is exactly the above teaching, that upon mentioning the name of the Tzadik, then and only then can we mention God.