“It was at Antioch that the disciples of Jesus were first called Christians” (Acts 11:26) The early Christians were known as disciples of Jesus.
To be a Christian then is not just to know about Jesus. Knowledge about Jesus can be found in the Bible. But the Bible is not a Christian. Knowledge about Jesus an also be found in the Catechism.
But the Catechism is not a Christian. All the knowledge we have about Jesus can be put on a silicon chip. But a silicon chip is not a Christian.
Link (here) the Jesuit Fr. K of the New Orleans Province, Fr K's blog Disciples of Jesus