In their sermons, most mainline Protestant clergy have not emphasized personal sexual morality in the last generation.

There may be a link between word - or the lack of it - and deed.Fifteen percent of the pastors serving mainline Protestant congregations surveyed by the Star Tribune said they had had an extramarital affair as an adult. That's three times more than pastors of evangelical and fundamentalist churches, who preach regularly on personal morality.

Also, 19 percent of surveyed mainline ministers told the paper that they have been divorced.

Infidelity and divorce are problems for Protestant clergy. Despite their sermons' retreat from such topics, most work in organizations that prize marital fidelity and that say the only valid sexual relationship is in a faithful heterosexual marriage. Moreover, if parishioners believe that their pastors aren't practicing what their churches teach, the pastors' credibility will be eroded.

Still, mainline ministers' personal behavior, approaches that of the general population. A new study based on Gallup Poll data shows that about 30 percent of Americans have been divorced, and that 67 percent of married people are still married to their first spouse and report being faithful to that spouse in the last year.

In his new book, based, in part, on the Gallup data, the Rev. Andrew Greeley, a Roman Catholic priest and novelist, says, "Marriage in America is in better condition than most married Americans think it is."

Said the Rev. Benjamin Griffin, "I would hope that the clergy are generally more morally conservative than (lay) people." He is president of United Theological Seminary in New Brighton and a United Church of Christ pastor.

"It's our job to uphold and proclaim the ethical values of our traditions. We don't expect the clergy to be better than we are, but we do expect them to behave. Fooling around is misbehaving."

Griffin said the survey's findings about fidelity and divorce show the result of mainline denominations' avoidance of personal morality matters in sermons and church teachings in the last half of this century. "For the last 50 years we have been gung-ho on righteousness in the public arenas, but we have neglected personal morality."