Teens Ages 13-19 Free Dinner Discussion: What is Roman Catholicism? Ratio Christi means "The Reason of Christ". Our mission is to equip high school students with the historical, philosophical, and scientific reasons for following Jesus Christ, and train them to be conversational evangelists with logic and evidence. Meetings are open to local teens ages 13-19, and we welcome Christians, skeptics, atheists, and young people of all faiths/beliefs.