German President Horst Koehler congratulated Swiss theologian Hans Kueng with a personal birthday letter on Wednesday, March 19: "As Christian, academic and publicist, you have tirelessly worked toward dialogue between denominations, religions and world cultures."
Kueng was born on March 19, 1928, in the Swiss canton of Lucerne and was ordained as a priest at the age of 26 in Basel.
He is a colleague of Pope Benedict XVI and, as a professor of theology in Tubingen, Kueng has been an outspoken critic of the Catholic Church since the 1970s. After questioning the infallibility of the pope and calling for an internal reformation of the Catholic Church, his permission to teach was revoked by the Vatican in 1979.
It wasn't until after the death of former Pope John Paul II that Kueng was allowed to enter the halls of the Vatican once again.
Though Kueng and the current pope share a common background, their theological views differ greatly. While Kueng has focused on inter-religious dialogue, Pope Benedict places priority on tradition and the unity of the Catholic Church. Nevertheless, the two maintain regular communication.
Click on the links below to read DW-WORLD.DE's past interviews with Hans Kueng and related stories on the Catholic Church.