The fact that we don’t have any writings from Jesus, or that he didn’t handwrite the Bible on his own is not a big problem for Catholics. While the Bible is essential, it is not the only means of transmitting the Faith from one generation to the next. For this, Jesus established his Church, which St. Paul calls “the pillar and bulwark of the truth” (1 Tim 3:15). This is why Jesus chose his disciples and groomed them. They would be the method of transmission.