The Catholic Church in Ballarat ''effectively facilitated'' child sexual abuse by leaving known paedophiles in ministry and was ''unChristlike'', former Ballarat Bishop Peter Connors conceded on Monday.

His predecessor, Bishop Ronald Mulkearns, made ''terrible errors'' and showed ''great naivety'' in moving paedophiles Gerald Ridsdale and Paul David Ryan from parish to parish despite knowing they were child abusers, Bishop Connors told the Victorian inquiry into how the churches handled child sexual abuse.

Bishop Peter Connors, Ballarat Diocese. Credit:Joe Armao

''I can't see how a bishop could possibly do the things Bishop Mulkearns did today,'' Bishop Connors said.

It was the first day that Catholic leaders had given evidence, marked by heightened tension in the gallery and, for the first time, the presence of an armed security officer.