Considering the Bible is itself a Catholic tradition, you must consider it to be a myth too.
Anyway, the word "myth" doesn't imply something is untrue or unchristian. A myth is just an ancient genre of literature, which actually is a part of Jewish and Christian literature (including parts of the Bible).
The doctrines of the trinity, deification of Yeshua, and physical resurrection are proto-orthodox doctrines, meaning they came from the Roman branch of Christianity which merged the native Roman religion with the teachings of Yeshua, this was done all over the middle east, but it was the Roman version which became dominant or "orthodox" by vurtue of its political power. This took place in the century or two before the Council of Nicea made Christianity the official religion of Rome.
With the alliance of Constantine and the Roman Church orthodoxy was born. The Roman "Catholic" church came into being after the Eastern Church split from the Roman Church.