The canon of the bible itself was determined by God. Flawed men used of God preserved the manuscripts and brought them together. While there were spurious manuscripts at the time they were not widely accepted so the canon developed over time as the Apostles inspired works were accepted as the Word of God.
Though the Early Church used the Old Testament according to the canon of the Septuagint (LXX), the apostles did not otherwise leave a defined set of new scriptures; instead the New Testament developed over time.
The writings attributed to the apostles circulated among the earliest Christian communities. The Pauline epistles were circulating in collected form by the end of the first century C.E. Justin Martyr, in the early second century, mentions the "memoirs of the apostles," which Christians called "gospels" and which were regarded as on par with the Old Testament.
A four gospel canon (the
Tetramorph) was in place by the time of Irenaeus, c. 160, who refers to it directly.
By the early 200s, Origen may have been using the same 27 books as in the modern New Testament, though there were still disputes over the canonicity of Hebrews, James, II Peter, II and III John, and Revelation. Likewise, by 200 C.E., the Muratorian fragment shows that there existed a set of Christian writings somewhat similar to what is now the New Testament, which included the four gospels and argued against objections to them. Thus, while there was a good measure of debate in the Early Church over the New Testament canon, there were also precedents for the current canon dating back to the second century.
Biblical canon - New World Encyclopedia
History shows you another false claim by your RCC. Cathode you put way to much stock in that institution. Read the bible for yourself and ask the Holy Spirit to guide you into a biblical understanding of His inspired word.