He might find reality too taxing,

 

so he confines himself in the sanctuary provided by the Bible.

Encourage him to learn history, recent history.  Visit historical landmarks.  Know the stories happened there.  This way, he still does not have to deal with "burdens" imposed by the reality surrounding him, but at least it is closer to the present.

Learning history helps him to see the present, thus gives him confidence to deal with reality.

Escaping reality is not a good way to grow up.

If he reads the Bible with the present reality in mind, he then is truely reading the Bible. To learn about human nature is part of growing up.

 

Give him some responsibility.  Remind him to be resposible for himself first.