The former Prime Minister's faith is claimed to have influenced all his key policy decisions and to have given him an unshakeable conviction that he was right.
John Burton, Mr Blair's political agent in his Sedgefield constituency for 24 years, says that Labour's most successful ever leader – in terms of elections won – was driven by the belief that "good should triumph over evil".
"It's very simple to explain the idea of Blair the Warrior," he says. "It was part of Tony living out his faith."
Mr Blair has previously admitted that he was influenced by his Christian faith, but Mr Burton reveals for the first time the strength of his religious zeal.
Mr Burton makes the comments in a book he has written, and which is published this week, called "We Don't Do God".
In it he portrays a prime minister determined to follow a Christian agenda despite attempts to silence him from talking about his faith."
Many of us had niggling suspicions about this even in the days leading up to the war, but this was also a time when we would not accept that the incidence of belief and influence of religion in society was anything but vanishingly small. How wrong we appear to have been. If this report is accurate it reveals an absolutely disgraceful state-of-affairs. The UK's participation in the Iraq war was not to protect our borders or our citizens. It was based on lies and manipulations of evidence to fulfil the agenda of a christian fanatic. How, in the 21st. century, in an advanced, supposedly civilised and democratic country can we have allowed this to happen?