A pastor, a football star, and the battle for a key Senate seat

When Raphael Warnock was six years old, his mother discovered him preaching his heart out in his room, huffing and puffing as he tried to imitate the soaring cadences of revival preachers he’d heard at church in Savannah, Georgia.

Some 115 miles inland, a young Herschel Walker was also gasping for breath, sprinting down the railroad tracks near his house as he embarked on a rigorous solo training regime that would transform him and his life.   

Raised in modest, Christian homes, both men harnessed an unusual drive and talent to...