Actor Chris O'Dowd thinks following a religion will eventually become as offensive and unacceptable as racism.

The Irish star of films such as The Sapphires and Bridesmaids says he grew up respecting people of faith despite his atheist views, but has become "less liberal" as he ages.

Actor Chris O'Dowd believes religion's days are numbered.

Now he says religious doctrine is halting human progress and brands it "a weird cult".

He also thinks US president Barack Obama had to overstate his Christian faith in order to get to the White House.