Pope Francis in a video message to the bishops of the Americas said Mercy is not a "theory to brandish" or "empty talk" but a memory - a call to remember our sins.
The message was released by the Vatican for the gathering of bishops from North, Central and South America and the Caribbean, who met for their continental congress for the Year of Mercy.
In whatever they do "and even way of doing theology," Pope Francis said, "it is about learning to show mercy."
The Holy Father told them that "mercy is learned from experience - in our own lives first."
