Who is James Pike from Valis and what is their importance?

A historical figure, Pike is Horselover Fat's cursory friend and hero. Pike enjoys a controversial career as an Episcopalian bishop, writer, television broadcaster, espousing what most Americans then consider radical social and theological views before, in 1969, he and his new wife disappear in the Israeli desert. Only she survives. Fat and Sherri Solvig, who likes to tease him about Pike's fatal incident, laugh at the idea that Pike might have refrained from drinking radiator water to save his life for fear that it contains antifreeze - in the middle of the Dead Sea Desert. Fat believes that the Sibyl of Cumae, the first-century protector of the Roman Republic, foresees Pike's death along with the Kennedy brothers and Martin Luther King, Jr. All are said to be defenders of the liberties of the Republic and religious leaders.