You can investigate and Study them until pigs begin to fly- but that still doesnt make it canon.
biblical scholars study them all the time, I’ve read most of them. They have some import as commentaries and histories of the beginning of Christianity and of the intellectual and spiritual infighting that came in the forming of Christianity.But as far as what we consider canon or scripture that has been measured by certain standards these documents do not fill the bill.from
www.catholic-resources.org
Four-Fold Role of the Evangelists as Authors (what they contributed, even if “God is the Author” of all scripture):
Selectors - from among the many things Jesus said and did, they chose which stories they wanted to include and which to omit.
Arrangers - they organized the materials in a particular sequence, not necessarily chronologically but often in thematic blocks.
Shapers - they adapted and edited the individual stories from their sources so as to emphasize the themes they wanted to stress.
Proclaimers - they were not objective historians, but preached the “good news” about Jesus in ways appropriate to their audiences.
Ten Stages of NT Formation and Transmission (with considerable chronological overlap, continuing down to today):
Some scholars propose only 3 stages (Historical Events, Oral Tradition, Written Texts), others 5 stages (Historical Events, Oral Tradition, Written Tradition, Editing, Canonization); the following schema more comprehensively lists 10 stages, many of which overlap:
The Historical Jesus - words are spoken and deeds are performed by Jesus himself during his lifetime on earth.
Oral Tradition - traditions and beliefs about Jesus are developed and passed on by early Christian communities.
Written Sources - some of the miracles and/or sayings of Jesus are compiled and recorded in early written documents.
Written Texts - individual letters, full Gospels, etc., are written with particular messages for particular situations.
Distribution - some writings are copied and shared with other Christian communities throughout the Mediterranean.
Collection - certain Christians begin collecting the letters of Paul and gathering together several different Gospels.
Canonization - four Gospels, several collections of letters, and a few other texts are accepted as authoritative scriptures.
Translation - biblical texts are translated into ever more ancient and modern languages: Latin, Syriac, Coptic, Armenian, etc.
Interpretation - the meaning of the scriptures is investigated on various levels: literal, spiritual, historical, social, etc.
Application - communities and individuals use the NT for practical purposes: liturgical, moral, sacramental, theological, etc.
Four Criteria for Canonicity (why certain books were eventually accepted into the NT Canon, while others were rejected):
Apostolic Origin - attributed to and/or based on the preaching/teaching of the first-generation apostles (or their closest companions).
Universal Acceptance - acknowledged by all major Christian communities in the Mediterranean world (by the end of the fourth century).
Liturgical Use - read publicly along with the OT when early Christians gathered for the Lord’s Supper (their weekly worship services).
Consistent Message - containing theological ideas compatible with other accepted Christian writings (incl. the divinity and humanity Jesus).