Independent Fundamental Churches, especially those in the KJV-preferred tradition, affirm Mark 16:9-20 as part of the authentic New Testament canon. While some textual critics note that the longer ending is absent from certain early manuscripts, fundamentalist churches have traditionally received it as Scripture based on the Textus Receptus and the broad manuscript witness of the church tradition.

The signs and wonders mentioned in Mark 16:17-18 are understood as confirming the Apostles' authority and the truth of the Gospel. These verses are used to support missionary zeal and confidence in God's power. The longer ending is taught as Scripture and applied directly to Christian faith and practice.