Sister Veronica Openibo, a Nigerian who has worked in Africa, Europe and the United States, spoke with a soft voice but had a strong message for the prelates sitting before her.
"We proclaim the Ten Commandments and parade ourselves as being the custodians of moral standards and values and good behavior in society. Hypocrites at times? Yes! Why did we keep silent for so long?" she said.
Openibo delivered her talk at the start of the penultimate day of a Vatican summit conference of some 200 senior Church officials convened by Pope Francis to confront what he has called the scourge of sexual abuse by the clergy.
She directly told Pope Francis, sitting near her on the dais, that she admired him because he was "humble enough to change your mind," apologize and take action after he initially defended a Chilean bishop accused of covering up abuse. The bishop later resigned.
"How could the clerical Church have kept silent, covering these atrocities? The silence, the carrying of the secrets in the hearts of the perpetrators, the length of the abuses and the constant transfers of perpetrators are unimaginable," she said.