A blogger set off an uproar in the Arab world by claiming he was God and hurling insults at the Prophet Muhammad. He is now behind bars and faces a potential life prison sentence on heresy charges for “insulting the divine essence.”

Residents of Qalqiliya, a West Bank town, say they had no idea that Walid Husayin—the 26-year-old son of a Muslim scholar—was leading a double life. He prayed with his family each Friday but secretly posted anti-religion rants on the internet during his free time.

Over several years, Husayin is suspected of writing blog posts that described the God of Islam as having the attributes of a “primitive Bedouin.” He called Islam a “blind faith that grows and takes over people’s minds where there is irrationality and ignorance.”

He is also suspected of creating three Facebook groups in which he sarcastically declared himself God and ordered his followers, among other things, to smoke marijuana in verses that spoof the Muslim holy book, the Quran.

At its peak, Husayin’s Arabic-language blog had more than 70,000 visitors, overwhelmingly from Arab countries. The visitors posted angry response comments and detailed death threats. Some formed Facebook groups against him.

His mother canceled his internet connection after she discovered articles on atheism on his computer, hoping he would change his mind. He began going to an internet cafe where, after spending several hours a day in a corner booth for several months, he aroused suspicion.

A cafe worker supplied snapshots of his Facebook pages to Palestinian intelligence officials. After monitoring Husayin for a couple months, officials arrested him on Oct. 31. He has not been charged but remains in detention, said Palestinian security spokesman Adnan Damiri.

Husayin is the first to be arrested in the West Bank for his religious views, said Tayseer Tamimi, the former chief Islamic judge in the area.

Two cousins of Husayin said his mother thinks he should receive a life sentence—both to restore the family’s honor and to protect Husayin from vigilantes. His father asked that reporters not write about his son to avoid public shame.

The Associated Press contributed to this report.