Yeah. Various Christian groups, et.al., would dearly love to have us accept various other ideas and have them included in the canon of Scripture, too. Here are a few examples of what some would like to have included in the new Testament:
The "Gospel of Thomas" [not the apostle], which for a time was held by some scholars to belong to the NT canon, ends with the absurd statement [which contradicts the rest of Scripture]:
"Simon Peter said to them: "Let Mary go away from us, for women are not worthy of life." Jesus said: "Lo, I shall lead her, so that I may make her a male, that she too may become a living spirit, resembling you males. For every woman who makes herself a male will enter the kingdom of heaven."
Some scholars wanted to include as Scripture the writing called the Didache. It is even quoted by some today as if it were an authority on the teaching on the early church or on the same level as the New Testament writings, yet it contradicts or adds to the commands of the NT at many points.
(For example, in the Didache Christians are told to let alms sweat in their hands until they know to whom they are giving (1.6); fasting is required on Wednesdays and Fridays but prohibited on Mondays and Thursdays (8.1); Christians are required to pray the Lord's prayer three times a day (8.3); apostles are prohibited from staying in a city more than two days (11.5) - (but note that the apostle Paul stayed 1 1/2 years in Corinth and 3 years in Ephesus); prophets who speak in the spirit cannot be tested or examined (11.7) - (a contradiction to the other Scriptures: 1 Cor. 14:29 & 1 Thess.5:20-21)
Luckily we don't have to worry about any of this because it is God Himself, via the Holy Spirit who assures the transmission of the text down through the ages. It doesn't depend upon human efforts.
"My sheep (in whom is my Spirit) hear my voice" [John 10:27]
Yeah, but Jesus and the Apostles quoted the Old Testament largely from the Septuagint which contains the Deuterocanonical books of Scripture. 300-350 references to the Old Testament are taken from the Septuagint.
I don't know why you seem to disregard this fact, or the fact that several Church Councils determined the Canon of Scripture (including the Deuterocanonical books) at the end of the fourth century.
Some scholars wanted to include as Scripture the writing called the Didache. It is even quoted by some today as if it were an authority on the teaching on the early church or on the same level as the New Testament writings
Christians place importance on the actions of the early Church since peers of the Apostles would have best understood Apostolic Tradition. Since the Didache is one of the earliest known Church documents, it is of great importance in understanding Sacred Tradition. The Church has never regarded the Didache as the equivalent of Sacred Scripture. Nor has the Church ever regarded the teachings of any Church Father, or even any Doctor of the Church, to be inerrant. The Church only regards as inerrant Its dogmatic teaching.