Pope acknowledges 'bad fish' in Church

Pope Benedict urged lapsed and lukewarm Roman Catholics on Thursday to rediscover their faith but acknowledged there are "bad fish" in the Church itself.

The pope made his comments at two large events before thousands of people in St. Peter's Square on the 50th anniversary of the opening of the Second Vatican Council, a far-reaching event in the Church's 2,000-year history.

"Recent decades have seen the advance of a spiritual desertification," he said in his sermon of a morning Mass, opening a worldwide "Year of Faith."

"We see it all around us ... the void has spread," he said.

The mass was attended by hundreds of Roman Catholic bishops as well as representatives of other Christian churches, such as Archbishop of Canterbury Rowan Williams. The bishops are in Rome for a synod, or conference, at the Vatican aimed at building a strategy to bring lapsed Catholics back to the faith.