The angel taught the three children how to pray..

Then he appeared a second time..
And this is part of what he said to them

..Pray! Pray very much! The hearts of Jesus and Mary have designs of mercy on you.Offer prayers and sacrifices constantly to the Most High..

Make of everything you can a sacrifice, and offer it to God as an act of reparation for the sins by which He is offended, and in supplication for the conversion of sinners.....