JANUARY 2002. Didier had arrived in the UK from Senegal and was knocking on his aunt's door. No answer. No one at home.

Didier was absolutely freezing. Until that moment he had thought a temperature of 19 degrees Celsius was cold. At a bracing -2 degrees, Britain felt like the coldest place on the planet. His fingers were heavy and numb with cold. He could see the headlines in his mind's eye: "African immigrant freezes to death on Tooting doorstep!"

Finally, hours later, his aunt returned from work. Shivering Didier found refuge in her home, snuggling under a mountain of blankets, trying to get warm.

It was a memorable - if miserable - arrival in the UK. And his family had said that it was such a great place to be.

Born Aboubacar Sidiki Douno, 26 year old Didier, as he likes to be called, is from a traditional Muslim family in Guinea, West Africa. His father, a government employee, has four wives. Didier is one of three boys and ten sisters in the large family.

His childhood was happy, though he wasn't much interested in praying five times a day like they taught him to in the Muslim religious school he attended.

Unfortunately, civil wars in neighbouring Sierra Leone and Liberia kept spilling over the borders into Guinea. Life in the country was unsafe. In 1995, Didier's father sent him to live with his uncle in Senegal, away from the fighting.

Didier's uncle was relaxed about religious observance. He let Didier do what he wanted and, though he fasted during Ramadan out of tradition, the teenage Didier essentially lived as he pleased. He was popular, got good grades, joined the basketball team at his high school and wanted to do a scientific job in his future; a geneticist, a biotechnologist - something cool like that.

Religion seemed futile, especially when he started reading philosophy. At the age of 12, he read books about Plato and Socrates, and argued with a Christian friend who tried to persuade him that God was real. "I took great pleasure in defeating my friend in the debates we had," says Didier, with a rueful smile.

At 18, Didier was enjoying life in Senegal when relatives in the UK sent word that he should come over. The UK was a great country, a place where Didier could develop his full potential, they said.

"They didn't mention the weather!" thought Didier as he stamped his feet and froze on his aunt's doorstep. But things improved from there. Didier quickly learned English and then took science A-levels at Kingston College. It was education, education and more education as he did Maths, Physics, Chemistry, Biology - then onto a year in business school - then he discovered computers, the beginning of an interest that continues to this day. Things were looking up for Didier as he flexed his intellectual muscles and made good progress.

But after six years things went wrong. Didier found that he was at odds with his father. In Guinean society, the head of the household is always right. Didier found he couldn't agree with his dad on a family matter - and things went sour.

"It was a painful rift," says Didier. "As the eldest son of the family a lot is expected of me, not only that I would always be dutiful and obedient, but that one day I would return to Guinea and take my place as the head of the family. I had to take a stand."

Communication broke down. Didier's dad stopped paying for his housing and education. Didier was suddenly alone; homeless, on the streets of London.

"For three months I had no place," says Didier. "The worst was going three weeks without a shower in the middle of summer."

Didier was looking for food in a bin outside an EAT restaurant when a man that people called "Big Rob" recommended he go to the London Jesus Centre for help.

Didier says, "I'd seen the Jesus Army in Leicester Square when I had been doing work as a nightclub promoter. I'd always thought 'Are you guys for real? No one wants to talk about God on a Friday night!'" Ditching his reservations, Didier went inside for a shower.

"That shower was so great!" says Didier. "No one in London cares about you when you are on the streets. At the Jesus Centre, I found friendship and warmth. The contrast was clear."

Didier met with Tim and Edwin who work at the London Jesus Centre. He was impressed with their patience and kindness; it made him curious. Mary, one of the workers at the centre, made Didier feel like "the most important person on earth". Amazing people! "They were friendly and real," he says.

Didier got a place to live again and got back on his feet. He got to know people at the centre and heard their stories. His curiosity grew - and so did his faith. In May 2009, he was baptised as a Christian - but still needed to cross the line into living for Jesus.

"I was 'one foot in the world and one foot in God's kingdom'. Living with my girlfriend, going clubbing - but knowing I needed to make a choice. We used to laugh at Christians on the TV, but now - I wasn't laughing any more. "

In August 2009, at a leaders training session at Cornhill manor, Didier had a decisive experience. "I was walking in the fields when I felt an amazing peace and a sense of belonging. I thought, 'That's it, I belong here.'"

Two months later, Didier and his girlfriend agreed to go their separate ways. Old friends were perplexed at the change in him, but Didier was set on living a new life.

This desire to led Didier to move into Christian community, which he did in January this year, the cold month of his first arrival back in 2002.

Says Didier: "Community reminds me daily of the preciousness of the kingdom of God, of the people around me." With vision to use his skills for building the church, Didier is asking God to increase his faith.

"I want to be a real disciple of Jesus and I know I have some work to do."

No longer out in the cold, Didier's heart has been warmed by the love of God; he's a changed man, ready and willing to live for Jesus with all that he's got.