Like many people who would call themselves Christian in Australia but don't go to church on Sundays there are numerous Muslims that have stopped observing the customs of their faith.
Perhaps you could say they have become Westernised, sending their kids to Western schools and so on.
That's what part of this war in Nigeria is about.
You have a poor population and a Government riddled with corruption overseeing atrocities committed by a group who are anti Western.
These groups punish people for attending Western schools by killing them and burning down their schools.
They want to enforce their own Islamic caliphate.
Those recent assassins in France grew up in France and lived a life of petty crime, presumably not religiously following Muslim customs, until they found a calling later in life.
Their calling seems to have been martyrdom, apparently brought about by feelings of outrage at the way the USA and the West treated their brothers in Iraq and it's aftermath.
They probably saw Osama Bin laden as a hero and an inspiration.
