St. Paul preaches the Gospel to the Gentiles. A Pharisee mocks the heart of the Law, the Gospel. Give me some of your stew, before I die. My children, pray the rosary every day. It can be your ladder to Heaven.
Costumes help focus children on their part in the play.
As helpful as costumes are, they are not necessary. Understanding their parts and what they are saying is even more important. Then the heart of the Bible story can imprint, leaving a lasting impression and depth of understanding on your children.