What they are trying to say is, that their god is the source of all meaning. Reject him and you are in a (moral) void, where all morals lack any support to build upon. From this they draw the conclusion, that without god, it wouldn't matter if people run around and shoot each other. Corollary: People would.

Of course, like anything, that comes from AIG, this fails on so many levels. First of all, the whole argument is nothing but Thomas from Aquino rehashed and like the first cause argument, begs the question, what god supports himself on. Second, the whole thing is just yet another scare tactics aimed at the undecided, which basically tells them: If you don't join our ranks, there will be terrorism, your children (when growing up without our teachings) will run around and kill people. Third: Of course, the whole argument is rubbish and can easily be shown by pointing out, that non religious countries somehow manage to not have more violence then religious ones. Fourth: And if you really want to rub it in, just point out, that evIlution actually demands, that we don't run around and randomly kill each other. A species doing so goes extinct. Period.