Mark Watson continues his quest to improve the world.

As broadcast live in November 2011 - he invites the audience join in via tweets and messages to work out how we can all make the world a better place.

He's nimbly assisted by:

Tim Key
Tom Basden.

Asking the big questions crucial to our understanding of ourselves and society - this time Mark asks - What is faith?

Its one of the most used, and feared, words of modern times. Yet these days, it's often used derisively about religious beliefs and so on.

Mark looks at odd things done in the name of 'faith', versus the obvious merits of having faith (belief that England will eventually win World Cup, ability to ride out difficult marriages).

Should we be more credulous and believe people like estate agents? Or LESS credulous and destroy our TV sets altogether in case we accidentally absorb lies?

Producer: Lianne Coop.

First broadcast live on BBC Radio 4 in November 2011. Show less