Born in Evanston, Illinois in 1932, Christopher got his start as a stage actor in the 1950s before moving into television and film. Christopher held a variety of guest roles on many 1960s shows including The Andy Griffith Show, The Patty Duke Show, and The Men from Shiloh; he would also land recurring roles on Gomer Pyle, U.S.M.C. – as Private Lester Hummel-, That Girl and Hogan’s Heroes.
Christopher landed his most famous role in 1972, replacing the actor who portrayed Father Mulcahy in the M.A.S.H. pilot. He would remain a series mainstay throughout the show’s 11 season run, and would reprise the character on the short-lived M.A.S.H. spinoff AfterMASH.
Christopher also held guest roles on shows such as The Love Boat, Good Times, Murder, She Wrote, and Mad About You among many others.
Christopher, whose son, Ned, is autistic, was an advocate for people with autism, devoting time to the National Autistic Society and recording public service announcements.