An Ohio native (Stark County), Pastor Gassman graduated from John Brown University in 1966 with a Bachelor of Arts in Bible, and finished his formal education at Faith Theological Seminary near Philadelphia, PA in the spring of 1969. He and his wife, Beverly, then moved to Morrow County, Ohio to serve with the Ohio Bible Mission at Peniel Bible Camp near Chesterville, Ohio.

Morrow Bible Church started in Pastor Gassman’s home at Peniel Bible Camp in 1983. He continued to serve both the church and the camp until 1998 when he transitioned from the camping ministry to serve Morrow Bible Church full time. In 2015, Pastor Gassman stepped down from the Senior Pastor position, and the church called him to continue ministry as Pastor Emeritus.

For more than 50 years, he served in various capacities in the ministry of Peniel Bible Camp. He was a member of the Ohio Bible Fellowship and served on the board of the Ohio Bible Mission.

The Gassmans have four daughters and twelve grandchildren.

In May 2023, Pastor Gassman was diagnosed with Guillain-Barré Syndrome, resulting in paralysis. He required nearly two years of special care.  

He went home to be with the Lord on Palm Sunday, April 13, 2025.

"I have fought a good fight, I have finished my course, I have kept the faith: Henceforth there is laid up for me a crown of righteousness, which the Lord, the righteous judge, shall give me at that day: and not to me only, but unto all them also that love his appearing."

2 Timothy 4:7-8