Kessler was moderator of the 1963 General Assembly of the former United Presbyterian Church in the United States of America (UPCUSA).
A native of St. Louis, Kessler graduated from the University of Dubuque and the University of Dubuque Theological Seminary. Later, he returned to Dubuque and earned his Doctor of Divinity degree in 1941.
Following his graduation from seminary in 1934, Kessler served pastorates in Farmington, Iowa and Fullerton, Neb. In 1940 he was called to be pastor of First Presbyterian Church of Hastings, where he served until his retirement in 1976. Following his retirement in 1976, Kessler went on to serve 15 interim pastorates.
During his tenure in Hastings, Kessler also served as president of the Nebraska Council of Churches, as a member of the board of trustees at Hastings College, as a member of the Omaha Presbyterian Seminary Foundation Board, and as the first elected moderator of the Synod of Lakes and Prairies.
In his community, Kessler was a member of Kiwanis for more than 35 years and served on the boards of the local Salvation Army and the Hastings Literacy Program.
Internationally, Kessler preached and taught in Chile, Egypt and Lebanon.
In 1998 he was given the President’s Award by Hastings College, where he continued to serve as an honorary trustee until his death. In 2007, he was named the University of Dubuque’s Alumnus of Distinction.