Updated

Pope Benedict XVI called Saturday for politicians, the media and world leaders to show more respect for human life at its earliest stages, saying embryos aren't just biological material but dynamic, autonomous individuals.

Benedict made the comments during a vespers service to mark the beginning of Advent, the period leading up to Christmas when the faithful mark the birth of Christ. This year, the Vatican urged bishops around the world to make the service a vigil for "nascent human life."

The service came amid continued fallout from the pope's remarks about condoms and HIV contained in a book-length interview published this week.

While stressing that condoms aren't a real or moral solution to fighting HIV, Benedict said people who use them are edging toward a greater morality because they're aiming to protect their partners from HIV — even when a pregnancy is possible.

His comments set off intense debate among theologians and lay Catholics alike amid confusion about what he meant and whether he was changing church teaching about artificial contraception. He was not, but the confusion nevertheless required not one but two papally approved clarifications from the Vatican spokesman.

As if to reaffirm church teaching on the sacredness of human life, Benedict stressed the need to protect human life from the moment of conception in his homily Saturday.

Science itself has shown how autonomous the embryo is, how it interacts with the mother and develops in a coordinated and complex way, Benedict said.

"It's not an accumulation of biological material, but a new living being, dynamic and marvelously ordered, a new individual of the human species," Benedict said.

He urged politicians, economic leaders and the media to promote a culture that respected life, decrying the "cultural tendencies" that seek to undermine it.

"Unfortunately, even after birth the life of children continue to be exposed to abandonment, hunger, misery, sickness, abuse, violence and exploitation," Benedict said.