This part of the Lord’s Prayer in Matthew, known as a doxology, has been questioned by scholars over the generations. Many feel that it was added later by the Christian church because it contains what they conclude to be language used much later than the days of Jesus. However, a very early Christian document called the Didache or “Teaching of the twelve Apostles” (late first century A.D.) contains the Lord’s Prayer, including this doxology, thus suggesting its antiquity. The Book of Mormon serves as an additional witness.