Maybe one of the most common arguments I hear from moderates, religious and nonreligious alike, is basically along the lines of "why bother? Just let them believe whatever." Everyone here basically knows our response to this, so rather than rehash, I will link to this article. You need not read past the subtitle:
http://www.msnbc.msn.com/id/29515505/
"Brazil girl, alleged rape victim, aborts twins
The procedure on the 9-year-old girl draws complaints from Catholic church"