Pope Benedict XVI has admitted there is 'much that could be criticised' in the Catholic Church.
The Pope was addressing up to 700,000 people outside Cologne at a prayer vigil as part of the World Youth Day festival.
John Paul II, in the last years of his 26-year pontificate, had apologised for a string of historic wrongs, including atrocities against Jews and the Church's contribution to slavery.
Pope Benedict's admission came towards the end of an address that was otherwise devoted almost entirely to spiritual matters and the challenges facing the young.
Earlier, in his first major address to Muslim leaders, Pope Benedict said they had a duty to help defeat terrorism and turn back the 'wave of cruel fanaticism' that uses religion to instigate hate.
The Pontiff said that 'terrorism of any kind is a perverse and cruel decision which shows contempt for the sacred right to life'.
Pope Benedict was speaking in Germany which is home to an estimated three million Muslims, most of whom are of Turkish descent. He has already met with Jewish and Protestant groups.
Tomorrow he will celebrate Mass with around 800,000 young people to mark World Youth Day.
