Please pardon the intense reaction. MotheringDotCom is a wonderful place, but on the issue of bris milah we Jews are at the receiving end of all sorts of insults here, including being called abusers, mutilators, and monsters. And that's just on the public boards.
Anyway, I'm not sure what you're looking for. If you're looking for a Jewish justification not to circumcise, you won't find one.
If you're looking for Jews who justify for themselves their own decisions not to circumcise, the no-circ groups and links will do fine for you.
If your purpose is for Jewish mamas who don't circ to give you khizuk (strength) in your decision, that's fine, and I'm sure you'll get that. But understand that those responses are incompatible with religious explanations.
If you're asking why are there all these laws that Jews seemingly don't follow, and then we insist on following that "barbaric" practice ... then that's a simple misreading of what Jews do and don't do.
And BTW there's no such thing as a "good Jew" or a "bad Jew," that's all nonsense that people put into your head. All we can do is learn. As far as being "confident in your Jewishness to explain circ'g your son or not," you shouldn't have to explain anything to anybody.
OTOH If you're looking to instigate an argument with observant Jews or Jews for whom the practice of bris milah is an important connection to their Judaism, then I won't oblige.
And I'm not going to try to convince you of reasons for a bris. A local Chabad rabbi could do it better ... (and everybody has local Chabad rabbis, they're everywhere
Forgive my presumptuousness (sp?) but BelovedBird's point I think was that we don't practice animal sacrifice because the Temple in Jerusalem no longer exists, not because it's no longer a part of the religious tradition. Our daily prayer services correspond directly to those sacrificial services ...
Anyway, sorry for the virtual verbal excess. Just a sensitive topic around here ...