There’s more to the singer’s faith than sunshine and blessings. The word icon, despite its clear religious roots, is generally used in a secular sense these days. A true icon, in this sense—a cultural figure who transcends genres and boundaries to win general adulation—is becoming a rare sight in our increasingly fragmented culture. Dolly Parton, argues writer Dudley Delffs, is one figure who unquestionably deserves the label. It’s easy to agree with that. The sweet-voiced singer-songwriter from East Tennessee has the powerful gift of creating music that speaks to people of all backgrounds and all tastes. From childhood, she had…