In 2008, journalist Adriana Carranca was living in Kabul and covering the war in Afghanistan, when she heard about a local pizza shop run by fellow Brazilians.
She says, at the time, Brazil had no relations with Afghanistan whatsoever. The countries didn't engage in commercial trade, and there were no diplomatic ties.
So the idea that a Brazilian couple — with two young kids in tow — had chosen Kabul, of all places, to open a food business struck her as odd.
"I was like, 'Oh no … They are probably drug dealers," she tells ABC Radio National's Religion and Ethics Report.
"It was in the middle of the war, it was very unlikely that someone would travel all the way from Brazil … to settle in Afghanistan to run a pizza delivery business."
Ms Carranca began ordering pizza and asking questions, but the family refused to open up.
She moved back to Brazil and kept calling. Eventually, the husband Luiz made Ms Carranca an offer:
"'Do you really want to know what I do in Afghanistan? Come visit us.'"
In 2011, she spent months with the family, and discovered that the pizza parlour was indeed a front.
Luiz was on an undercover mission to spread evangelical Christianity.
What's a missionary?
There are around 430,000 foreign Christian missionaries, according to the latest research published in the International Bulletin of Mission Research.
These are people who are sent to perform educational, philanthropic or humanitarian duties in a foreign country, but generally the priority is to promote Christianity.
According to Cristina Rocha, a cultural anthropologist and director of the University of Western Sydney's Religion and Society Research Cluster, evangelisation — or spreading the 'Good News' — is central to Christianity.
"There's a passage of the Bible [that says] you should engage in the Great Commission, which is: you should go and evangelise," she explains.
"[For example, if] you are at the bus stop and you see somebody who is not well, you want to help, you talk to them, but you also tell them of Jesus."
The Great Commission is spelled out in the New Testament in Matthew 28:16-20. The passage reads: "go and make disciples of all nations, baptising them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you".
Foreign missionaries are usually sent by a specific church or religious organisation.
Although, Professor Rocha points out that some people — like the Brazilian pizza shop owner, Luiz — may choose to operate and evangelise independently.
Where do they come from?
In the past century, the nationality of Christian missionaries has changed significantly.
"[Missionaries] used to be from Europe, from the US, coming to the Global South," Professor Rocha explains.
Now, it tends to be the opposite. It's a movement known as 'reverse missionisation'.
"The centre of gravity of Christianity has moved to the Global South — two-thirds of the 2.5 billion Christians live there," says Professor Rocha.
"People from the Global South who are ... Pentecostal charismatics, they see Europe as a place that has no God … and [believe that] they need to go there to evangelise.
"Sending missionaries overseas to establish branches of their own churches gives prestige to their churches in their country [of origin]."
In 1970, 88 per cent of Christian missionaries came from Northern America and Europe.
Today, that figure sits at just 53 per cent.
The remaining 47 per cent is made up of missionaries from the Global South, with many coming from Brazil, South Korea, the Philippines and China.
As identified in the International Bulletin of Mission Research, "missionaries today are sent from everywhere and received everywhere".
However, countries with the largest Christian populations receive the largest numbers of missionaries, often because they're more likely to offer invitations and sponsorships.
How soccer helps evangelise
In the Middle East, it became increasingly difficult for American missionaries to enter Muslim countries following September 11, Adriana Carranca says.
"Especially after 2003, with the war in Iraq, the anti-Americanism became very acute, and it was suicidal to send American missionaries."
"The leaders of this global mission movement, who were essentially Americans, realised, 'Well, we have an army [of] ... people [already] converted to evangelical Christianity … across Latin America, and to a certain extent in Africa and Asia, that we can send [instead]."
Soon, she says, these churches began realising that Latin Americans, particularly Brazilians, were incredibly successful in their missions.
Brazil is an ethnically diverse country, and Ms Carranca believes this helps residents adapt to different cultures when living overseas.
"We have the largest diaspora of Lebanese people, for example, [and] … Brazil is the largest exporter of Halal [meat] to the Middle East," she says.
The fact that Brazil's government wasn't involved in wars in the Middle East was another drawcard.
But perhaps the most important factor was soccer.
"People love Brazil because of soccer," Ms Carranca says.
"So soccer became really the most powerful visa for Brazilian missionaries to go across the Middle East and talk to Muslims … which Americans couldn't do."
Indeed, soccer — or football — was one of the topics that helped the pizza shop owner, Luiz, connect with Kabul locals.
"Once he said, 'I'm Brazilian', oh my God, people would smile … and start talking about soccer," Ms Carranca says.
"That was the door to talk about Jesus."
The dangers of doing missionary work
Of course, Christianity isn't new to the Middle East.
As Ms Carranca points out, the Coptic Church has existed in the region for millennia.
"But they don't try to convert Muslims," she adds.
"They learned how to co-live with Muslims without clashes."
Evangelical Christianity — which includes Pentecostalism — is practised very differently.
"[It's] a movement that was born in the US, but exploded in Latin America for its live masses and music," explains Ms Carranca.
According to Professor Rocha, Pentecostals believe they have a personal relationship with God.
"He's your best friend, so you ask everything from God, [like] what you should do today, what you dress [in], what your mission in life is," she says.
"Everything [in] your life is permeated by the Holy Spirit, by this intimate contact with God — outside of churches and inside of churches."
And this individualistic evangelical faith was the type of Christianity that Luiz hoped to spread through his pizza parlour.
"Everything that they did was secret," says Ms Carranca, who chronicled the family's experiences in her book Soul by Soul: The Evangelical Mission to Spread the Gospel to Muslims.
"They would speak in code. They didn't use their real names.
"Luiz would host these baptisms at his own home, in the bathtub."
Ms Carranca says preaching Christianity — or any other religion — in Afghanistan was forbidden.
"Those who convert, who leave Islam, can receive the death penalty for apostasy," she says.
"I interviewed many, many foreigners who were Latin Americans, who were expelled or even killed in the field for being missionaries."
In 2023, 20 Catholic missionaries were killed, according to the Vatican's news agency.
The death toll of foreign missionaries from other denominations remains unclear.
Earlier this year, an American couple who were working as missionaries in Haiti were fatally shot by gang members after leaving a youth group activity at a church.
Despite the real dangers to him and his family, Luiz believes his missionary work has been worth it.
Today, he assists some 300 Brazilian missionaries across majority Muslim nations.
Ms Carranca says — even though she worried for her safety on the streets of Kabul — Luiz was always at ease.
"He didn't seem to feel scared," she recalls.
"He would joke with people on the streets. He would hug the Afghans.
"He just felt free."
