SOLVED. Children/YA: fiction, series about a post apocalyptic world where society is based on religion. Priest can summon spirits. The story follows a young boy who is told he has to become a priest. [s]

[Anna]

This young boy finds out that the priests use projections to simulate ghosts and do not actual summon the spirits.. The priests argue against technology, but use technology to keep the population in line.
This book was read about 20 years ago by my boyfriend when he in his early teens. It is part of a series.

[Sue]

The 'Sword of the Spirits' trilogy by John Christopher? https://en.wikipedia.org/wiki/Sword_o...

[Anna]

I think that's it! Thank you Sue!!