He played a key role in establishing sports ministry in the UK.
The Welshman found fame through his partnership with presenter Des Lynam during the BBC's coverage of Wimbledon.
The organisation, Christians in Sport, said it was "deeply saddened" by his death and called him a "pioneer".
Founder, Andrew Wingfield Digby said: "Gerald Williams and Alan Godson were really the key players in establishing sports ministry in the UK.
"Backed financially by Kenneth Frampton at the Deo Gloria Trust, they were the first to catch the vision of 'reaching the world of sport for Christ' being promoted by Eddie Waxer.
"We have lost one of our very greatest pioneers."
Barbara Slater, director of BBC Sport, said: "Gerry was one of the finest tennis commentators of our time.
"His famous Wimbledon commentary and his on-screen partnership with Des Lynam will be remembered with fondness by everyone at BBC Sport.
"He was a man of great talent and will be sadly missed."
