Francis was speaking after a four-day meeting which he had opened by calling for "concrete measures" on tackling priests and handing 114 senior bishops a roadmap to shape the debate on how to stop a global scandal.
"If in the Church there should emerge even a single case of abuse – which already in itself represents an atrocity – that case will be faced with the utmost seriousness".
Pope Francis also called on for an "all-out battle" against a crime he called abominably and that should be "erased from the face of the earth".
"I make a heartfelt appeal for an all-out battle against the abuse of minors both sexually and in other areas, on the part of all authorities and individuals, for we are dealing with abominable crimes that must be erased from the face of the earth. This is demanded by all the many victims hidden in families and in the various settings of our societies."
He also vowed that the Roman Catholic Church would "spare no effort" to bring abusers to justice and will not cover up or underestimate abuse.
"Here I would reaffirm that the Church will spare no effort to do all that is necessary to bring to justice who has committed such crimes. The Church will never seek to hush up or not take seriously any case. It is convinced that the sins and crimes of consecrated people are further tainted by infidelity and shame. They disfigure the countenance of the Church and undermine its credibility."