Bernard, he's an interesting guy. He's the vicar (like a priest) of Saint Christopher's Church, Lucy's godfather, and Laura's university sweetheart. That's a lot of stuff to put into a minor character.
He started his religious work as an Army Chaplain and the work that he did gave him a view of religion that you probably wouldn't expect from most priests. Seriously, for a priest, he doesn't seem to have that much faith. Like this:
God only answered the prayers of the young and healthy, the ones who asked for love, or to get what they wanted for Christmas, or to pass their exams. For the disillusioned middle-aged or the elderly, it struck him as just one hopeless petition after another. (21.41)
It was no surprise, therefore, that his bond with the Almighty, the most intense of his life, involved long and difficult conversations more than actual worship. (30.1)
That does not sound like a happy priest. But maybe—just maybe—they make for a pretty good one.
So why did he want to become a priest in the first place? Out of the sheer goodness of his heart.
Bernard wanted very badly to believe that he and God had a single goal, and that the goal involved the eradication of suffering. Not that he believed, exactly, that suffering could be eradicated. But he believed in the process, the desire to make things better. Without human perfectibility as a goal, he could see no purpose to life on earth. (30.2)
Interesting isn't it? Bernard believes in human perfectibility, in humans improving life on Earth. Not in waiting for God to solve things—which is good, because we won't hold our breath for Bob to fix that problem.
In fact, Bernard sort of gives us a human version of Mr. B. They both want to end suffering and make things better. They both also see that they can't wait for Bob/God to fix things. They have to take everything into their own hands. For entirely different reasons, Mr. B and Bernard are stuck cleaning up after Bob's mess.
Rosoff has them chat at the end of the novel, and we couldn't have been more excited. We were totally cheerleading for them to be BFFs and talk about their shared God troubles. But Bernard just ends up thinking that Mr. B is some loony. Makes you think twice about the crazy guy who hangs out in front of the library, right?