The former fiancee of martyred German theologian Dietrich Bonhoeffer has given 38 of his letters to Harvard's Houghton Library.

The letters, written from a German prison camp and smuggled out by a friendly guard, show Bonhoeffer's more personal side--"a new level of intimacy"--according to the Reverend Paul Lehman of the Union Seminary, a close friend of Bonhoeffer's.

Excerpts from eight of the letters are printed in an article on Bonhoeffer that Mrs. Maria von Wedemeyer-Weller, his fiancee, wrote for the newest issue of the Union Seminary Quarterly Review. The remaining letters are so personal that Mrs. von Wedemeyer-Weller has stipulated that no one may look at them without her express permission.

Bonhoeffer was 37, and Maria von Wedemeyer 19, when they were engaged in 1943. Bonhoeffer had come back to Nazi Germany from America voluntarily to join the resistance movement. A few months after their engagement Bonhoeffer was arrested and imprisoned.

Hope

At first Bonhoeffer was in an ordinary prison, and his fiancee was able to visit him. At this time that he wrote a series of letters to her expressing his great loneliness and discouragement. In her article, Mrs. von Wedemeyer-Weller said the letters reflect his hope that he would some day be released and be able to marry her.

Bonhoeffer was transferred to a maximum securtiy Gestapo prison in 1944, when his involvement in a plot against Hitler--"the 20th of July Movement"--was discovered. He was able to write one last letter to his fiancee in December, 1944; he died in 1945.

Bonhoeffer has had a great influence on modern theological thought, Harvey G. Cox, associate professor of Church and Society in the Divinity School said yesterday, because of his affirmative view of the secular elements of society. He tantalizes present-day theologians because he died before he was able to explain some of his phrases, such as "religionless Christianity."

Cox said that Bonhoeffer is the model for many "involved" ministers and priests. Many theologians claim Bonhoeffer inspired the "death of God" theory, but Cox said this is still a subject of controversy.