Rejecting Infant Baptism.

"His (Andreas Karlstadt) understandings of liturgy, the church, baptism, and the Lord's Supper were based upon what he considered the teachings of the Bible alone. He rejected the Lutheran doctrine of predestination. He rejected infant baptism is a Sacrament, refused to baptize infants, and advocated adult baptism as a sign of Faith. His view of church rejected all hierarchy and emphasize the equality of members. The pastor calling was not to a higher status, but to an office performed only for the sake of order."

- J. Denny Weaver. Becoming Anabaptist. 2nd Edition.