Republican presidential candidate Ben Carson has a painting of himself and Jesus hanging in his house.

The Guardian visited Carson in his Maryland home, and found the painting on display in the hallway. Jesus, wearing a white robe, is pictured with his hand on Carson's shoulder, the two smiling gaily.

It's another insight into the faith of the candidate, who has repeatedly professed his devout Christian beliefs throughout his campaign. The 63-year-old retired neurosurgeon is vying for Republican frontrunner – a title he is currently only just being beaten to by Donald Trump. In a recent conference call Christian Today took part in, Carson claimed that he only decided to run after God "open[ed] the doors".

He recalled saying, "Lord, this is not something that I particularly saw as part of my bucket list, but if you really want me to do it, you'll have to open the doors...If you open the doors I'll walk through them. Close the doors, I'll gladly sit down."

A staunch pro-life advocate, Carson has been baptised twice into the Seventh Day Adventist Church. Engraved into one of the walls of his home is Proverbs 22:4 which speaks of the importance of humility, and there's no doubt he takes his faith seriously. "The most important thing for me is having a relationship with God," he once told CNN. "To know that the owner, the creator of the universe loves you, sent his son to die for your sins, that's very empowering."

Every single one of the Republican candidates professes a Christian faith, something that is apparently seen as vital in the political race – despite more Americans than ever claiming that they don't believe in God. A 2014 Pew Research Centre poll found that US citizens are less likely to vote for an atheist than any other type of candidate, including ones who have never held office. 

But in fairness to Carson, his faith doesn't appear to simply be an election tactic. Despite some of his more ridiculed statements – including that a Muslim should never be US President, and his insistence on championing Creationism – it's evident that his beliefs are sincerely held. 

Last week, he downplayed his critics. "Some people believe in the Bible like I do and don't find that to be silly at all, and believe that God created the Earth and don't find that to be silly at all," he told reporters in Miami.

"The secular progressives try to ridicule it any time it comes up. And they're welcome to do that."