The Didache (or “The Teaching of the Twelve Apostles”) is an early Christian document found in 1873 which may date back to the end of the first century. It contains instructions about church administration and is surprisingly similar to the instructions found in Moroni 2-6.
Evidence Central documents 17 points which are covered in both the Didache and Moroni including baptism, ordinances, meeting together, iniquity, unrepentant sinners and the confession of sins.
While there are also many differences, it is interesting that even the wording is similar on many points.
If Joseph Smith wrote the Book of Mormon on his own, why are the instructions to the church in the New World similar to those given in the Old World? Did Joseph have enough understanding of the administration of the church to be able to include so many relevant points?