This was a 1948 country gospel song written and first performed by the legendary Hank Williams. Williams typically used the song to close his shows. With poetic lyrics, such as “I wandered so aimless, life filled with sin/I wouldn't let my dear Savior in,” the song was written about Williams’ Christian religious convictions and hope for redemption despite his lifelong struggles. 
These struggles progressed with several years of back pain, alcoholism and prescription drug abuse that deteriorated Williams’ health. He divorced his wife Audrey, and was dismissed by the Grand Ole Opry for unreliability and frequent drunkenness. Williams died on New Year's Day in 1953 at the age of 29 from heart failure exacerbated by pills and alcohol. 
“I Saw the Light” is a beautiful song about spiritual truth, but as with all believers, our life is not determined by what we hear, see or say. It’s determined by faith in who we follow day-by-day.