Benedict, the former Cardinal Joseph Ratzinger, listed top priorities of his papacy in a message read in Latin to cardinals gathered in the Sistine Chapel for the first Mass celebrated by the 265th leader of the Roman Catholic Church.
He said his "primary task" would be to work without fail to reunify all Christians and that sentiment alone was not enough. "Concrete acts that enter souls and move consciences are needed," he said.
The new pope said he wanted to continue "an open and sincere dialogue" with other religions and would do everything in his power to improve the ecumenical cause.
The message was clearly designed to show that Benedict was intent on following many of the groundbreaking paths charted by John Paul, who had made reaching out to other religions and trying to heal the 1,000-year-old schism in Christianity a hallmark of his pontificate.
Benedict referred to his predecessor several times in his message, including a reference to the late pope's final will, where John Paul said he hoped new generations would draw on the work of the Second Vatican Council, the 1962-65 meeting that modernized the church.
"I too ... want to affirm with decisive willingness to follow in the commitment of carrying out the Second Vatican Council, in the wake of my predecessors and in faithful continuity with the 2,000-year-old tradition of the church," he said.
John Paul, with Benedict as his doctrinal enforcer, supported council reforms but cracked down on what both men considered excesses spawned by the changes, including calls for priests to be allowed to marry and admission of women into the priesthood.
A conservative on issues such as homosexuality, the ordination of women and lifting the celibacy requirement for priests, Benedict has led the Vatican's Congregation for the Doctrine of the Faith -- a position he used to discipline church dissidents and uphold church policy against attempts at reform by liberals and activist priests.
Joy over the selection of a new pope immediately mixed with worries that Benedict could polarize a global church, whose challenges include growing secularism in rich countries and inroads by evangelical groups in regions such as Latin America.
