A super-Christian. The one that knows every bible verse, every story, every answer to any bible related question. They may or may not have friends outside of their church/youth groups, and it is often thought that they don't. They often are quite evangelical to people, and will shout "Jesus loves you!" from their cars to people in the streets. They are insanely annoying, even to other Christians.
God rocker - "Hey! Jesus loves you! John 3:16!"
Atheist - "Wow, what a God rocker..."