Evanescence actually try to distance themselves from the lable "Christian rock music". There is obvious influence, but their intent is not to make Christian music. Here is an excpet from an article about them:
Ben Moody made to distance his band from the Christian community. He told Rolling Stone, “We’re in no way a ministry band. It just doesn’t have anything to do with our music.” Another interview even found Moody dropping f-bombs. “We’re actually high on the Christian charts, and I’m like, ‘What the (expletive) are we doing there?’”
I know now they don't consider themselves to be "Christian." Now that Amy Lee is the only remaining original member, and as far as I know, she's been vacationing and living with her boyfriend (the lead singer from the South African band "Seether"), she is definitely not acting like a Christian. She still has an awesome voice, and I admire the fact that she has a healthy feminine body and a healthy body image, which is something you don't often see today.