U2 musician Bono has criticised modern Christian music for its 'lack of honesty'.

The comments came out of a conversation with Eugene Peterson, a pastor and theologian best known for the "Message" translation of Bible. They discussed the poetry of the scriptures and in particular the book of Psalms which Bono described as "brutally honest."

In a documentary entitled The Psalms, the star said: "I often think, 'God, why isn't church music more like that?'"

The short film explores the pair's unlikely relationship after Bono first praised Peterson's work in 2002. They eventually met but only after Peterson had turned down an opportunity to meet the U2 singer while he was completing a piece of work.

Interviewer Dean Nelson expressed his shock that Peterson could turn down an invite from the Irish star. "It's Bono, for crying out loud," he told Peterson. "Dean, it was Isaiah," Peterson responded, referring to his unfinished work.

In the film the two discuss their shared love for the Bible. and the vulnerability of its authors.

"In the Psalms you have people who are vulnerable to God in a good way. They are porous and open," said Bono.

"I find in Christian art a lot of dishonesty, and I think it's a shame," he continued.

"I would love if this conversation would inspire people who are writing these beautiful... gospel songs, write a song about their bad marriage. Write a song about how they're pi**ed off at the government. Because that's what God wants from you.

"I am suspicious of Christians because of this lack of realism."

In the documentary Peterson talked about the difficulty he had translating the Psalms.

"It's not smooth, it's not nice, it's not pretty, but it's honest," said Peterson. "I think we're trying for honesty, which is very, very hard in our culture."

You can watch an extract of the film below.