The terrorists desperately want this to be about religion. They want this to be about Muslims vs the rest. If they can make it that, if we in the west will believe that THAT is it, the terrorists can speak directly to all the 1.6 billion Muslims in the world and recruit from them. They will justify their horrible actions vs other Muslims with the reasoning that they did it for all Islam which was "threatened".
It is a political struggle within Islam. Every western nation is walking on eggshells to keep it so. Don't support the terrorists by saying "They said Allahu Akbar, it's religious".
Want to dishearten Daesh? Challenge them and spit in their face, show them their actions is for nothing? Walk with Christian if you're Muslim and a Muslim if you're a Christian (or atheist or whatever).