"I thank God for the talent he has given me and I take it seriously," he said at a press conference.
The American came through a three-man, four hole play-off with Louis Oosthuizen and Australian Marc Leishman.
He said the power of prayer helped him achieve victory: "I was reading bits of scripture to myself, things like Psalm 24, Verse 7. I've been reading them all week."
"I was standing there reciting some scripture that I have in my book just to keep me in the moment and I was getting prepared for a tee shot on 18," added Johnson, who won the Masters at Augusta National in 2007.
"But I said it back in 2007. I feel like God gave me the ability to play a game. I try to take it very seriously. I realise it's just a game. I'm just a guy from Iowa that has been blessed with a talent and this game provides great opportunity."
In the second Monday finish in Open history, Johnson defeated South Africa's Louis Oosthuizen and Australian Marc Leishman in a four-hole aggregate play-off after the trio had finished tied on 15 under par.
Masters and US Open champion Jordan Spieth was just a shot behind alongside Australia's Jason Day, both men failing to birdie the 18th to join the play-off.
