That puts Yeary, who heads the church attended for the past 15 years by the US Republican presidential candidate firmly in the US Southern Baptist mainstream, and in line with the Republican Party.
He offers a sharp contrast to Democratic contender Barack Obama's former preacher Jeremiah Wright, who has stirred controversy with his fiery comments on race and America.
Obama had been seen by some analysts as having an edge over McCain on issues of faith because of his adult conversion experience and his ease in talking about his faith. But his own preacher has proven a political liability.
In a country where religion and politics often mix, 25 per cent of American adults count themselves as evangelical Christians, giving them huge influence as the country heads to the Nov. 4 presidential election to succeed President George W. Bush.
McCain draws some support from this group but many conservative Christians are uneasy with him because of his support for stem-cell research and his past criticism of leaders in the movement.
Yeary, pastor for the 7,000-member North Phoenix Baptist Church, professes little interest in politics and prefers to focus on preaching and spiritual guidance. But McCain's affiliation with Yeary will do him no harm in wooing support from the key Republican base of evangelical Christians.
"John and I are friends, he has called on me to minister to the family in times of challenge and difficulty," he told Reuters in a telephone interview.
McCain, a former prisoner-of-war in Vietnam, was raised in the Episcopal Church but has been attending Yeary's church for about 15 years. Yeary declined to comment on McCain's reluctance to finally undergo a baptism ceremony, a key ritual of the faith.
"John and I are having continual dialogue about his spiritual pursuits," Yeary said.
In an interview last year with InsideCatholic.com, an on-line Catholic forum devoted to issues of faith, McCain said he liked Yeary's "message of reconciliation and redemption which I'm a great believer in".
"And so I began attending North Phoenix Baptist church and I'm grateful for the spiritual advice and counsel that I continue to get from Pastor Dan Yeary."
McCain, like his pastor, is staunchly opposed to abortion rights but Yeary said the pair had never discussed the issue.
"Have we talked about abortion? No," Yeary said. "I believe that abortion is wrong and I believe that it is a very, very poor choice ... I believe it should be outlawed."
The 69-year-old Yeary adheres to the Southern Baptist belief that gay marriage and homosexual relations go against Biblical scripture, hot-button issues for many in the United States.
"The Bible is pretty clear about it, in my opinion it specifically calls it a sin. I also am a sinner and you are a sinner. ... Did Jesus Christ love homosexuals? I'm sure he did," Yeary said.
Obama's preacher by contrast sparked howls of protest for his angry sermons over what he called racist America, charging that the September 11 attacks were retribution for US foreign policy and claiming Washington was the source of the Aids virus.
Wright was Obama's pastor in Chicago for two decades but the Illinois senator, locked in a tight battle with New York Sen. Hillary Clinton for the Democratic presidential nomination, distanced himself from Wright in a widely hailed speech addressing race issues earlier this week.
Obama would be the first black US president.
"In the United States, the sacred cow is the concept of the nation-- someone who is a religious minister can say almost anything they want and not get into trouble in the political realm unless they go after the nation," said David Domke, a professor of communication at the University of Washington.
Yeary was sympathetic as a fellow pastor and said while he did not agree with Wright's comments, all preachers eventually got caught in the trap of their own exuberance.
"All preachers have a tendency to overstate because our passion is so intense. But I thought Obama did a fine job in response. He preserved his friendship with his pastor while disagreeing with him," Yeary said.
"I'm sure John McCain would probably say the same thing about me if he were asked 'So, do you agree with everything your pastor says?'" he added with a laugh.