Sir Walter L. Mack Jr., distinguished pastor and teacher at Union Baptist Church in Winston-Salem, N.C., will be guest speaker at Clark Atlanta University’s C. Eric Lincoln Lecture Series. The program starts Thursday at 10:50 a.m. in Davage Auditorium in Haven-Warren Hall. A noon luncheon and student scholarship forum will be held in the boardroom of the Thomas W. Cole Jr. Research Center for Science and Technology. Both facilities are at the CAU campus, 223 James P. Brawley Drive.