From '9-1-1: Lone Star' to Mercy Ships: Actress Sierra McClain answers God's call to faith-driven service

Sierra McClain is used to playing characters with conviction. Whether as Nessa Parker on "Empire" or Grace Ryder on Fox's "9-1-1: Lone Star," the 31-year-old actress has always been drawn to roles that require emotional depth and strength of spirit. But in her latest project, McClain isn't playing a character. Instead, she is stepping into a calling from God.