If you've ever skirted past the man on a soapbox in your local town centre who's shouting about salvation – you're not alone. Most of us have, probably more often than we'd like to admit, avoided the watchful eye of those who brandish Bibles and loudly proclaim that The Day Of The Lord Is Near while shoppers, in a wonderful display of British propriety, scurry on and pretend they haven't just been told they're facing eternal damnation. We question these preachers' motives, assume they're a bit mad, and quietly feel smug that our own conversations with non-Christian friends involve a lot less talk about the burning pits of Hell.

But for two open air evangelists interviewed by Christian Today this week, it's not ridicule that's their primary concern, but arrest.

Preacher Rob Hughes has just been awarded £2,500 in damages for wrongful arrest, false imprisonment and breach of his human rights after being arrested in September 2013, accused of homophobia by a passer-by. Held in custody for 11 hours at the time, he was released and told no further action would be taken due to insufficient evidence. Hughes had recorded himself on a dictaphone in his pocket which proved that he hadn't even mentioned homosexuality, but says that the police chose not to listen to it. A full-time evangelist, he and goes out every week to share the gospel with those on the street who would never think of entering a church. Andrew Geuter, who was arrested in April this year, has been doing the same for over 20 years.

Geuter was taken in by police following a complaint that he too had made homophobic comments – he maintains that he "most certainly hadn't". A statement from the Christian Legal Centre, which supported both Hughes and Geuter, said he "had been preaching on the Christian definition of marriage arguing that the present Government has destroyed marriage in its determination to redefine marriage to include relationships between people of the same sex."

So why the hostility?

Hughes, who trained as a pastor, says that open air preaching is a form of ministry that's "misunderstood even by Christians".

"By nature, it's very public," he told Christian Today. "Some ministries take place within the confines of a church building...whereas open air preaching is on the street, out in the open. It's a ministry that has to be done well because it's so public."

The image of a zealous bigot preaching fire-and-brimstone at anyone who walks past is a misrepresentation, he insists. Though these individuals certainly exist, many open air preachers, like Hughes and Geuter, simply want a chance to share their faith with a wider audience and encourage people to think openly about Christianity.

"It began with my conversion, I just wanted to tell people about Jesus – it's as simple as that," Geuter says. "You don't get many opportunities in the normal course of life, but my wife and I started as missionaries in Albania and I began open air preaching there with a colleague...I found that [it] was a terrific way to reach people. We preached to very big crowds there, but what drew me to it was the desire to tell people about Jesus, backing it up biblically with the Great Commission."

"Speaking to the masses can be powerful and effective. We live in a culture where people obviously need to hear the gospel, but they also need to be educated about what the Bible says, and what the gospel actually is," Hughes adds.

"Ultimately we endeavour to share the gospel every time we go out, and bring people to the foot of the cross and show them they need a saviour, but sometimes people need to hear, 'Look, here's a book called the Bible'. It's a great opportunity. It's great to help people know what the Bible and Christianity are all about, but it's got to be done well."

One problem, Hughes says, is that when people have seen street preaching done badly, it can shape their view of Christianity in a negative way. "Open air preachers have a responsibility not to be alien...we don't want to be so far removed," he explains. Rather than just standing and reeling off a sermon, he tries to engage with anyone who stops to listen, using anecdotes and humour.

Any suggestion that the evangelism technique is outdated is misguided, Geuter says. "We get to speak to about 3,000 people in a year, most of them young, and that's great.

"Most people in this country, and I'm not trying to be offensive here, are absolutely ignorant of the gospel – they haven't a clue! And the government isn't going to tell them, the education system isn't going to tell them, and sadly most branches of the Church won't tell them either, so the task devolves to nutcases like me."

Both men are adamant that while some people might oppose their style, there is a wider issue of religious liberty and the freedom of speech at stake. "In the past, the word tolerance used to mean 'I disagree with you, but I put up with you and I don't oppress you'...The word's been changed to mean 'you must accept me'," Hughes says. "I cannot live in a society where you're not allowed to have an opinion. That's not democracy; it's a dictatorship."

He wants "a robust law that takes into account the rights of Christians". Currently, one group of people are given preference over another, he adds. "How is that just?"

Geuter agrees. "We live in days of a funny kind of equality – it isn't my understanding of equality... We live in a democracy, and we're supposed to have freedom of speech. Anybody should be free to speak about what they believe in – atheists have a wonderful time on the media, why not Christians?

"Do we live in a democracy, or don't we? Do we have free speech, or don't we? We have a long heritage of outside preaching that goes right back beyond the Middle Ages; it's not as though it's something new. The whole Methodist denomination arose out of open air preaching, as did the early Baptists, so you can't cut that off as though it's nothing.

"People don't go to church, and even if they did, they very often wouldn't hear a good presentation of the gospel. That's not a criticism of the Church, it's just how it is. My view as a disciple of the Lord Jesus Christ is that I have to take the gospel to them."