In a message to over 250 Catholic bishops at the Vatican today, Pope Benedict XVI said it was hypocritical to exclude God and religion from public life.

“A tolerance which allows God as a private opinion but which excludes him from public life, from the reality of the world and our lives, is not tolerance but hypocrisy,” the pope said in the homily he gave at a three-week-long synod’s opening mass in St Peter’s Basilica. “When man makes himself the only master of the world and master of himself, justice cannot exist. Then, arbitrariness, power and interests rule.”

Today marked the beginning of the pope’s first synod since his April 19 election, Agence France-Presse reported. The conference will focus on theological issues linked to Holy Communion, as well as abortion and divorce.

People who ignore God pose a threat to “the Church in Europe, Europe itself and the West,” the pontiff said.

Bishops will debate how to address falling church attendance in Europe, the U.S. and Oceania, where the number of faithful attending Sunday mass has dropped well below that of Africa and Asia.

The synod was expected to deal with various issues surrounding abortion, including how to address Catholic politicians who support the practice, especially when those politicians seek to take Communion.

The news service quoted a working Vatican document that said Catholics who “publicly supported immoral choices such as abortion” were committing mortal sins.

The document also condemned those backing politicians who “openly supported abortion or other terrible crimes against human life, justice or peace” or who succumbed to “temptation or corruption,” saying all were acting against the church’s teachings.

“Some receive communion while denying the teachings of the Church or publicly supporting immoral choices in life, such as abortion, without thinking that they are committing an act of grave personal dishonesty and causing scandal,” the document said.

The event got under way without four bishops from China who were prevented from traveling to the Vatican by Beijing’s Communist government. According to AFP, three of the bishops were part of China’s state-approved church and one was from the underground Catholic church.

Note: Read our discussion guidelines before commenting.