Necessary in my meaning was medical necessity. Circumcision can sometimes be necessary, though these conditions(that I know of tend to present long past the infancy stage. In my experience, adolescence or later. Since you still ascribe to some customs of your faith, despite your questions, I would not consider you an athiest. To me, you're still Jewish enough to warrant that classification. Of course, if you think differently, then I'm being a jerk and will cede a very heartfelt apology.