Prior to his service as a bishop of the church he served three Free Methodist congregations—Lexington, Kentucky, during his seminary years (1953-1956), New Westminster, B.C.
Bastian has authored several books, including: Belonging, the long-used and often-updated membership training book of the Free Methodist Church; God's House Rules, on biblical principles for family life; The Pastor's First Love: And Other Essays on a High and Holy Calling; and From Kitchen Chair to Pulpit: A Memoir of Family, Faith, and Ministry.
Bastian has also written hundreds of articles, appearing primarily in Light and Life, the magazine of the Free Methodist Church, as well as in Christianity Today, The Lutheran, and The Upper Room.
Beginning in the late 1980s, Bastian and President Neil Hightower of the Canadian Nazarene College worked with Canadian denominational leaders to establish a chair in Wesleyan studies at Tyndale Seminary, Canada's largest Protestant seminary.
[2] In 2016 Greenville University (formerly Greenville College) established the Donald N. and Kathleen G. Bastian School of Theology, Philosophy, and Ministry, as well as the Donald N. Bastian Chair of Pastoral Theology and Christian Ministry.