Monograms of Jesus. A monogram is one or more letters put together to form a symbol. Monograms date back to the first century and are among Christianity’s oldest symbols. Monograms that are connected to Jesus Christ (Chi Rho, etc.) are called chrismons. The term chrismon comes from two Latin words Christi Monogramma which mean “monogram of Christ.” Chrismon trees, a tradition started in American churches in the mid-1900’s, is one way in which chrismons can be displayed in a church.