Ben Cooley is a man on a mission, and he wants you to join in. The call: to rid the world of modern-day slavery. It might sound ambitious, but Cooley, the CEO of abolition charity Hope for Justice, is convicted.

As a glance at his owns story shows, he knows transformation well. A trained opera singer, Cooley once set his heart on the stage, but an encounter with the reality of slavery changed his life. He attended an event where the dire statistics were shared: 27 million held in slavery across the world, 1.2 million children trafficked every year. Cooley thought to himself: 'If that was my daughter I would do something.'

His next thought changed his life: 'It's always somebody's daughter.'

There began a dream – to pursue a bold vision, 'a world free from slavery'. At only 26 years old he booked Birmingham's NEC Arena and saw just short of 6,000 people come to hear about modern-day slavery and the vision to see it end. He founded and now serves as the CEO of Hope for Justice (HFJ), which in the past three years has rescued more than 330 victims of trafficking in the UK. He describes the story of HFJ in his debut book Impossible is a Dare.

Cooley tells Christian Today how his Christian faith has been impacted by his journey.

'My faith has been encouraged that there's so much good in the world. I see the darkness and the exploitation. I've seen children in horrendous situations,' he says. 'The systematic abuse of women. Victims of forced labour held in refrigerators for five years.

'But I've seen the good of humanity...I've seen the Church rise up and speak about this issue. I've seen politicians and businesses addressing their supply chains. I choose to see the good in every situation.'

In the fight against slavery, it could be easy to become cynical or discouraged. Cooley said that his biggest challenge is accepting 'not being able to help everyone' –accepting that with all the resources he might have, inevitably there will be cases of need where, Ben says, 'I can't do anything about it.'

He adds: 'We're not going to give up, we see it as a dare but it is the hardest thing you're going to walk through.' It is a difficult journey, but Cooley invites people to 'see pain as your passport to your future'.

His encouragement to those who might be tempted to despair of indifference is the heart of his book. 'If I can do it, you can do it,' he says.

'I want the reader to dare that they can stand against the giant of impossibility.'

He adds: 'We are architects of this world. We get to choose what it can be. What you tolerate, you never change.

'People say, "It can't be done" – why not? Yes it can. I'm a rebel, but I hope I'm a good rebel. You say you can't help hundreds? I'm going to help millions.'

What then can be done to join in Cooley's vision?

Firstly, Cooley says, people can become givers, financially supporting Hope for Justice. Secondly they can set up prayer and abolition groups in their communities, fundraising and mobilising people into action. Lastly, Cooley suggests booking a speaker to speak on behalf of HFJ and share the vision to a group.

Cooley says that a love of joy is central to the work of HFJ. 'We're an organisation that laughs...oh, do we laugh. Joy is intrinsically linked with strength. We're going to speak life, not death. We're going to be a fun group of people who want to change the world.'

Cooley says he's 'absolutely' seen that joy help the lives of the victims he works with too: '[The other day] I was rolling around laughing with them because joy is contagious. We need to be serious about the situation, I'm not irreverent, but what they need is someone to laugh, to bring them to a place of enjoying life again.'

HFJ has grown into an organisation based in eight locations in five countries across the world, rescuing hundreds of trafficking victims. It has won the support of celebrities like Stephen Fry and Bear Grylls, and has been meeting with international leaders like Donald Trump and Theresa May to ensure combatting slavery is on the political agenda. Cooley says there's a long way to go, but he's encouraged to see leaders taking it seriously.

'Nine years ago I wouldn't have thought we'd be where we are,' Cooley says. 'And I hope that's the case for the next nine years. I pray that freedom just becomes the norm. We want a world free from slavery so we have to keep on growing.'

Cooley's driven enthusiasm for this vision seems to be unstoppable, and whatever struggles he faces, he says it's the hope of 'changed lives' that keeps him going. He says: 'We want to inspire people that change is possible, but you need to get on and help us. We're going somewhere, our final destination is a world free for slavery, if you believe, join us. Come on! Why aren't you on the bus?'

You can read more about Hope for Justice here.

You can purchase Impossible is a Dare here.