Christianity as you know it was created 325 (no one knows if it actually was 325) years after Jesus died, and that too under the “auspecies” of Constantine I, the Emporer (a staunch pagan who only wanted to unify the Roman/Byzentine Empire).
Much of the Roman Pagan and Mithra ideology (the reason why Jesus is considered as the “son” of God) comes from the settlement reached at the Council of Nicea in 325AD where all of the Gospels that were accepted were adhered to thereafter and all Gospel versions declared as unacceptable were considered heresy and forced out of the belief system.
Some of the belief can be reconstructed from the Dead Sea Scrolls but even then, we do not know if they are the initial versions of the “Hadith” of Jesus, or of a Divine message delivered to him by an angel.