The issue is an illness (a physical or mental illness), not religion.
So he was a Relativist? No surprise there.
(Reader, now the same mental disorder is demanding we drive the US Economy into the Alps in order to stop the Earth from bursting into flames. It demands a RIGHT to murder pre-born babies in their mother's womb. And it also finds that sexuality which deviates 180 degrees from the human physiological norm, is perfectly normal... and as a result those afflicted with it, should have the means to marry anything it finds itself attracted to, be it a person of the same gender, multiple people of the same gender, minor children of the same gender and/or livestock... all of which are analogous to flying the entire human race into a mountain.
So all you need to decide is are YOU for that, or against it?
The Co-Pilot was clearly saddled with a disordered mind. And the evidence is that he was influenced by those who have a long history of using such people to destroy the lives of others. THAT HE WILLINGLY FLEW AN AIRCRAFT INTO A MOUNTAIN, IS,
in and of itself... Prima fascia EVIDENCE OF ISLAMIC INFLUENCE.)