We can say as follows: Every sin is BAD!! But every sin relates to the individual who commits the sin. So we don't view it as if all of the Jewish people are sinning. There is an obligation of ערבות - that every Jew is responsible for the actions of every other Jew, but the act itself relates to the individual. The sin of giving one's child to Molech is different. This is a sin that impinges on the GENERATIONS. That is an ENTIRELY different story. This sin relates the the Jews as a community by connecting the generations. This sin is REALLY BAD NEWS. Not just a personal indiscretion but one that bears upon the entire community. Since the sin relates to the community, it will also cause great spiritual harm to the entire community. A פגם in the כלל! Every other sin relates to the individual - even if many people commit the sin - a פגם in the יחיד. Horrible but not the end of the world. Here the sin relates to the totality. Almost the end of the world.
Now we can understand why the pasuk emphasized Geirim. One would think that the proper, official Jewish community excludes Geirim who are outsiders [see Kiddushin 75a] and thus the severity of this sin wouldn't apply to them. In order to disabuse us of this mistaken notion, the pasuk says that Geirim ARE included in the prohibition.
We also understand the emphasis of the pasuk that עם הארץ ירגמוהו באבן. Since there was a פגם in the כלל, it must be rectified by the כלל. The nation for whom the earth was created and Eretz Yisrael was given [as per Rashi] has been harmed and they need to fix it by carrying out retribution. [See Ramban פסוק ג].
Trust me - there is a TON more to say....
I hope Hashem gives me the life, health and financial means to say it....
Trust me - there is a TON more to say....
I hope Hashem gives me the life, health and financial means to say it....
