PLAYBOY, Penthouse and even Maxim are banned from the clubhouse. Gangsta music, too, and cursing is frowned upon, so those who succumb to the temptation – and this week there may have been a few – do so in hushed tones. Newspapers, sports and car magazines and the Bible – in particular, the Bible – are the reading material of choice and it is not unusual for front-office executives and players to join in prayer.

Welcome to Coors Field, the home of the Colorado Rockies Major League Baseball (MLB) team, where Game Four of the World Series will be played tonight. An inspired end to the regular season, in which the Denver-based Rockies won 14 of their final 15 games, resurrected their playoff hopes after they looked dead and buried. This and the New York Mets losing six of their last seven games, and the San Diego Padres losing their last three, propelled the Rockies towards their first appearance in the World Series, the climax of America’s baseball season, after they prevailed over the Arizona Diamondbacks 4-0 in the National League championship series.

If some divine intervention was at play in getting them this far – and some sublime ball-striking from Matt Holliday – it seems to have deserted them against the Boston Red Sox. The team of David Ortiz, Manny Ramirez, Kevin Youkilis, Curt Schilling and Daisuke Matsuzaka took a commanding 2-0 lead into Game Three after demolishing the Rockies 13-1 in Game One at Fenway Park and following up with a 2-1 win, again in Boston.

“We need to take care of business at home,” admitted Troy Tulowitzki of the Rockies. “We’ve got our work cut out for us but it isn’t over.”

Nor will their faith be shaken under the strain of the challenge now facing them. When Charlie Monfort, the Rockies chairman and CEO, became a Christian four years ago, after years of partying led to him serving an 18-month probationary sentence for “driving while impaired”, his conversion had a profound and almost immediate impact on his baseball club. Quietly, the Rockies became an organisation guided by Christianity, “open to other religious beliefs”, USA Today reported last year, “but embracing a Christian-based code of conduct they believe will bring them focus and success”. Character became a more valued element in the criteria for player recruitment. When Denny Neagle, a pitcher with a $51.5m (£25m) long-term contract, was arrested in December 2004 for soliciting a prostitute, his second brush with the law inside 14 months, the Rockies terminated his contract. It cost the organisation $16m in severance pay to ensure that he did not play again in the Rockies uniform.

Bible study sessions on Tuesday afternoons are usually attended by up to eight players, who openly discuss the scriptures and family life. “If they were Catholic or Baptist or didn’t believe in God but were quality players and good people and good teammates, there would be a place for them here,” said Matt Herges, a relief pitcher playing for his seventh club. “But I do see a lot of quality people in this clubhouse.

“This is the tightest-knit group I’ve ever been around. You wonder if some people are going along with it just to keep their jobs,” says Mark Sweeney, who was with the Rockies in 2003-04. “I pray every day, but I don’t want something forced on me. Do they really have to check to see whether I have Playboy in my locker?”

But even as the Rockies slipped to an early deficit against the resurgent Red Sox in the World Series, Monfort remained convinced that the club is following the right path. “Christians, and what they’ve endured, are some of the strongest people in baseball,” he says. “I believe God sends signs and we’re seeing those.”