Bear Grylls' friends are shocked that he has become a spiritual mentor to Russell Brand

Russell, 48, said on social media: "I want to thank Bear Grylls and my mate Joe, the two men that stood either side of me and flanked me for the baptism itself. Week one as a Christian has been amazing. The ceremony itself was incredible. I feel changed, transitioned ... nourished and held."

However, friends of Bear, 49, are shocked by his involvement.

A source told the Daily Mail newspaper: "It makes perfect sense when you view this as a faith issue. Anyone who repents is saved, and if you have strong belief like Bear then that is the only consideration. Only God judges! But I am a bit surprised."

But lifelong Christian Bear insisted it was a "privilege" to support Russell on his journey to Christianity.

He told the paper: "Faith and spiritual moments in our lives are really personal, but it is a privilege to stand beside anyone when they express a humble need for forgiveness and strength from above. Friendships when we go through tough times are worth so much."

The pair met last year when Brand took part in the National Geographic show 'Running Wild' with Bear Grylls'.