The only religion causing war right now is Islam.
* several groups fighting local governments to set up religious states, like ISIS, Al Shabab, Boko Haram
* several areas where Muslims are fighting to overthrow the local government and have Muslim only areas but not specifically to set up an Islamic state, from the Philippines to Urgyurs in China to northern Nigeria to Muslim enclaves in the EU where police won't go
* Islamic infighting, Sunni vs Shia and both of those killing Almaddhi and Sufi, especially bad in Iraq, Syria, Pakistan, Bangladesh
* Muslims moving into an area and then intimidating and even killing locals, like those in Thailand, Burma. They've been murdering Buddhist teachers who taught children science, because it wasn't haram.
So right now, there is a religion causing war - Islam, as it seeks to either overthrow secular governments to impose religious ones, dominate other groups with Islamic law or killing other Muslims.