You won’t know real adventure in your life if you’re a slave to your mobile phone, warns Britain’s most famous survival expert. Bear Grylls is a television phenomenon, with gargantuan audiences tuning in to watch his exploits in deserts, mountains, jungles and the wilderness – often in the company of luminaries such as Barack Obama and Julia Roberts.

But the 50-year-old father of three is more than an action man. He has won a global following because his celebration of resilience, courage and simple kindness strikes a chord with billions in a wired age. This former SAS soldier is increasingly opening-up about his faith and he encourages everyone to find room for adventure in their everyday lives – even if they are busy parents with little spare time or cash.

“Adventure is a state of mind – it’s how we live and how we interact with others and the world; it’s how we parent as well,” he enthuses. “You don’t need to go to the ends of the world to have a great adventure with your kids. Sometimes just a camp-out in the back garden is an adventure.”

He wants adults to help young people use their phones with discipline and “understand the consequences of too much screen time”. “A phone should be there to serve you and empower you for connections and information, not there to make you a slave to it,” he says.

Seeking the “outdoors and real adventure,” he argues, is a “much more attractive alternative” to spending hours glued to a screen.

He follows his own advice. His wife, Sharam, and lads Jesse, Marmaduke and Huckleberry have a home on a “small Welsh island hideaway”. He says that “hands down” this is the most beautiful place he knows.

Such escapes are not a regular experience for most of his fans, but he believes there are simple steps we can take to connect with nature and boost our mental health. He encourages us to search out fresh air and sunlight and spend “some moments each day barefoot on grass if we can find a park nearby”.

“Little things like this go a long way to boosting our all-round health, lowering anxiety and improving our day,” he says.

But how does a serial entrepreneur with unceasing travel commitments and projects switch off and focus on his loved ones? He has frank advice for men who want to be the best possible husbands and dads.

“Keep family first in all you do,” he says. “It’s so key. It’s no good being successful in the world’s sense but to have broken relationships all around us. That’s not success.”

He insists you should not “feel bad to put your family first,” arguing that happy and balanced people “tend to work much more effectively anyway”. Bear remembers advice he received on how to be a “great dad” – “love your wife and create a great life for the whole family”.

“That’s not about money,” he says. “That’s about having that adventure state of mind and a kind, loving faith-filled heart and environment for them to grow up within.

“We can’t always achieve all this, obviously, but it’s about the intent and doing our best. That’s starts with knowing the goal.”

Bear has known adversity first-hand. When he was 21 and in the SAS a parachute accident in Zambia left him with a broken back in three places.

A gruelling journey of rehabilitation followed but at the age of 23 he was standing on the summit of Everest. He believes his creator give him a second chance – and he tries to live by what he calls the “great pillars” of life, “purpose and love, with kindness and tenacity”.

“Life isn’t about what we achieve,” this hyper-achiever says. “It’s about how we live and the effect we have on those around us.”

His love for the military runs deep. He is Honorary Colonel to the Royal Marines Commandos and the British Army Foundation college, and he prizes the “camaraderie, values and careers that the armed forces provide to young people who want a better future than they maybe have at the moment”.

“We need ever more of that,” he adds. “Not just for national defence but also for national pride and purpose which are the foundation blocks of strong society.”

When asked to name his most inspirational figure, he points back two millennia.

“My hero has always been John the Baptist,” he says. “He lived a wild life, outdoors, eating bugs and honey, surviving the desert and swimming in the river Jordan.

“He then gave his life for his best friend and cousin, Jesus.”

Bear is among the highest profile Christian believers in modern Britain. He has written The Greatest Story Ever Told, an account of the life of Jesus seen through the eyes of those who lived beside him.

He describes it as the “ultimate love story”. He set out to write it as “a thriller” but “without changing one word of Jesus’ from the actual Bible”.

Bear starts each day by getting down on his knees to “ask for forgiveness and help” and says that “having a strong Christian faith has been the great light and strength in my life”.

The Old Etonian says his simple childhood faith “kind of got overrun by school religion” and it has taken him “a lifetime to untangle that and realise that Jesus came to bring life not religion”.

“They are very different things,” he insists, adding: “I like the vulnerability that faith allows. To know we are loved regardless of our failings and that with Christ within us we can do anything.”

There were reports earlier this year Bear was on the shortlist to become Britain’s ambassador to Washington DC, though the top diplomatic job eventually went to Labour grandee Lord Mandelson. Bear’s father, the late Sir Michael Grylls, was a Conservative MP but standing for election and jumping into frontline politics is an adventure his son can live without.

“I’m not sure I could handle being hated by 49% of the population, however hard you try and well you do,” he admits.

However, he is at ease in the company of world leaders, having spent time in the wild with Indian Prime Minister Narendra Modi and trekked in Alaska with Obama. Would he like to take President Trump on an expedition?

“Never say never!” he says. “Watch this space.”