The Vatican has unveiled some new sins for the 21st century, such as genetic manipulation, pollution and social injustice.
Archbishop Gianfranco Girotti, the Vatican's number-two official for sins and penance, told L'Osservatore Romano that he saw bioethics as posing the greatest risks for the human soul.
"(Within bioethics) there are areas where we absolutely must denounce some violations of the fundamental rights of human nature through experiments and genetic manipulation whose outcome is difficult to predict and control," he told the Vatican's official newspaper on Sunday in an interview headlined "New Forms of Social Sin."
The Roman Catholic Church has previously spoken out against stem cell research that requires the destruction of human embryos, believing that life begins at conception.
Girotti also attacked drugs, saying they "weaken the mind and obscure intelligence."
On the growing gap between rich and poor, he said it causes "an unbearable social injustice."
Pope Benedict has made several strong statements on the environment in recent months, saying problems like climate change had become critical to humanity's future.
Catholicism has two basic types of sin: Venial, which are relatively less important and forgivable, and mortal.
Mortal sin can include acts like abortion and murder, although the church doesn't keep a well-defined list.
Mortal sins can cause a person to go to Hell unless confessed to a priest, who then absolves the sinner in God's name.
With files from The Associated Press
