Riley's sermon, entitled "The Hidden God," will be presented during the 10 a. m. worship service at the First Presbyterians Church.
The minister will continue his "mystery bag" children's sermon series during which youngsters try to "stump the pastor" by putting personal "treasures" in small bags and challenging Riley to create a message from the contents.
Sunday School, which is open to all area children, follows the children's sermon.
The adult choir, directed by David Nunez, will perform special Lenten music during the service.
Riley has been an ordained minister since 1985 and served as the pastor of three Baptist churches over a period of 20 years before turning to journalism full-time in 1997.
His weekly column, "The Irreverent Reverend," appears in The Press on Fridays.
The Rev. Barbara Macfie will preach and administer Holy Communion on Sunday, March 3, with Riley returning to the pulpit on March 10. Macfie will also ordain and install recently elected members of the Session and the Board of Deacons.
The 123-year-old, handicapped-accessible Presbyterian church at Third and E. Highland Aves. has extra parking available in the new municipal lot next to the Christian Education Building on East Highland Avenue.
The church provides child care during all worship services.