The demonic figure on the front cover may not look too authentic, but the spirituality driving Ira and Charlie Louvin on these gospel-tinged country tunes is very real. Whether the Louvins are testifying to their faith with tent-revival exuberance on “There’s a Higher Power” or warning of the wages of sin on the tragic “The Kneeling Drunkard’s Plea,” they bring a life-or-death urgency to everything they sing here. No matter if they were delving into the spiritual or the secular, nobody boasted a more goose bump-inducing vocal blend.