"After Jesus -- The First Christians" (4 p.m. and 7 p.m., CNN): CNN investigates the tumultuous early years of Christianity -- from the crucifixion of Jesus Christ to the conversion of Constantine,

"After Jesus -- The First Christians" (4 p.m. and 7 p.m., CNN): CNN investigates the tumultuous early years of Christianity -- from the crucifixion of Jesus Christ to the conversion of Constantine, the Roman emperor who first legalized Christianity in 313 A.D. This two-hour documentary examines how they originally spread their message, despite infighting as well as widespread persecution by Rome. CNN examined archaeological evidence and consulted with authorities to answer numerous questions, including maybe the biggest one: How did Jesus and his followers triumph over Roman persecution to establish a worldwide faith?
"Great Performance: Renee Fleming" (9 p.m., PBS): Recorded at Germany's Mainz Cathedral, Renee Fleming performs a lush selection of sacred Christmas music, backed by a full orchestra and boys choir.