1917, Mr. Fred R. Body began approximately 45 years of service as teacher of the Ladies' Bible Class until his death in 1964. In the mid 1940s, the class was renamed to the Women's Body Bible Class in his honor. The class merged in 1970 with the Men's Golden Rule. It continues to this day under the name Body Bible Class.

July 3, 1918, member Reginald W. Smith made the supreme sacrifice in France. He was honored by his family with a memorial window in the church.

April 5, 1922, the Rev. Kenneth P. Otten was called as the third pastor of Holy Trinity. During his tenure, the Sunday school enjoyed great growth and church debt was reduced from $31,000 to $6,000.

1930s, economic depression, alterations to the Sunday school rooms, and redecoration of the nave increased the indebtedness of the church. But local benevolence became a well-organized, intensive program. The church provided a steady stream of coal and groceries to a considerable number of members. Erwin Biery, grandfather of current member Wilbur Matz, and father of Elsie Van Doren and Zelda Matz, saw to the deliveries. A milk truck driver by vocation, he probably used his delivery truck for this charitable purpose.

March 2, 1932, the Rev. Benjamin Lotz was installed as fourth pastor. His pastorate covered the years of World War II. His regular contact by letters and visits with more than 50 youth in the armed services were remembered with gratitude and affection. Five of them made the supreme sacrifice in the war. They were Robert Paul Jones, William Albert Jones, Louis Emerson Miller, George Byron Sandoe, Jr., and Russel Artz.