As a member of the Quorum of the Twelve, Wirthlin was accepted by the church membership as a prophet, seer, and revelator.

Wirthlin served in the LDS Church as bishop of the Bonneville Ward in Salt Lake City from 1955 to 1964.

The day he was released as bishop he was called to serve in the stake high council and was set apart by Joseph Fielding Smith.

On December 1, 2008, Wirthlin "had gone to bed at his Salt Lake City home, and died peacefully at about 11:30 pm of causes incident to age."

[4][5] On January 2, 2009, when the Utes won the Sugar Bowl, all of the Utah players wore a commemorative sticker on their helmets with the initials JBW in his honor.