He converted to Christianity under the ministry of Billy Graham, becoming a temperance movement supporter and running several times for political office.

He also composed music and acted in motion pictures with cowboy stars, including Gene Autry, Roy Rogers and John Wayne.

In 1949 after years of struggle with alcohol, Hamblen converted to Christianity at a Billy Graham crusade in Los Angeles, and was soon fired from his radio program after refusing to do beer commercials.

He subsequently gave up gambling and horse racing, and entered Christian broadcasting with his radio show The Cowboy Church of the Air, which ran until 1952.

[6][7] That evening, also Graham's first coast-to-coast television broadcast, Hamblen shared about his faith and sang/spoke his signature hymn "It Is No Secret (What God Can Do)".

The song would go on to be sung by popular singers Rosemary Clooney, Kate Smith, Jim Reeves, Wayne Newton, Leslie Uggams, Jo Stafford & Gordon MacRae (duet), Anne Murray, Tom Netherton, Eddy Arnold, Pat Boone, Johnny Cash, Elvis Presley, Hank Snow and Ernest Tubb.

[8] "This Ole House" was inspired during a hunting trip in the High Sierras with John Wayne and guide Monte Wolfe.

[1] In 1955, Hamblen had a hit single with "Open Up Your Heart (And Let the Sunshine In)" (B-side "The Lord is Counting on You"), performed along with his family under the name "The Cowboy Church Sunday School."

Hamblen was accompanied by wife Suzy, daughters Veeva Suzanne and Obee Jane (Lisa), and two of the girls' friends.

[10] "Open Up Your Heart (And Let the Sunshine In)" was sung on an episode of the television cartoon series The Flintstones in the mid-1960s by characters Pebbles and Bamm-Bamm.

[2] Hamblen supported the American temperance movement and ran as the Prohibition Party's candidate for U.S. president in the 1952 presidential election.

[12] Previously, Hamblen ran for California's 11th congressional district seat as a Democrat, losing to Carl Hinshaw in the 1938 election cycle.