Christianity and Christ are two separate things. The names of political affiliations rarely capture the actual goals of the policies. Conservatives are against preserving many things, and liberals are against allowing many things.
All the barbarism, societal regression and cruelty aside, I don't even think it's much of a deterrent seeing how the guy is an Islamist and their whole thing is martyrdom for their beliefs... If anything, it's giving him more exposure and setting an example for fellow extremists to follow.