The mixing of politics and religion has taken a new turn in Michigan, where a Republican congressman is urging fundamentalist ministers to help unseat a Democratic colleague so that creationism can be taught in public schools.

A "Dear Pastor" letter written by Republican Rep. Mark D. Siljander that opposes the reelection of the Democratic incumbent from his neighboring district, Rep. Howard E. Wolpe, states:

"The minority viewpoint of evolution is taught to our children in the public schools, paid for by your tax money, rather than the equally valid position of creationism."

The letter attributes this to the election of "liberals like Howard Wolpe" and urges the pastors to support his Republican opponent, Jackie McGregor, in November.

Wolpe, who is Jewish, said he believes he was singled out because of his religion. He noted a line in the letter that reads: "You can make the difference in helping send another Christian to Congress."

"I didn't know religious tests were part of running for office," he said.

Siljander said that particular wording was unfortunate, and that no religious test was intended.

Meanwhile, a spokesman for McGregor expressed surprise at the letter's focus on creationism as an election issue.

"It is not something we have ever mentioned in our campaign," said Ian Modelski, McGregor's press secretary. "I don't even know what her position on evolution and creationism is."

Siljander, who was elected to Congress in 1981 with the help of fundamentalist groups to fill a vacancy created by the resignation of David A. Stockman, describes himself in his letter as a "born-again evangelical."

His letter, which is co-signed by two state senators, begins: "Dear Pastor: As elected officials serving under the authority of the Lord Jesus Christ, we felt it our responsibility to contact you before the general election . . . . "