At the Second International Conference on World Evangelization (Lausanne II) in 1989, evangelist Luis Bush charged the gathered mission workers with bringing the Gospel to what he called the “10/40 Window” – a geographic stretch running across Africa and Asia that is home to most of the world’s Hindus, Buddhists, and Muslims. Also known as the “Resistant Belt,” much of this stretch would be aflame within two decades, after the attacks of September 11, 2001, gave way to another Bush’s global “War on Terror.”

Adriana Carranca’s gripping Soul by Soul brings these developments together in looking at how evangelical missionaries have worked to win the souls of Muslims in the 10/40 Window amid the upheavals of the War on Terror and Arab Spring. Carranca tells this global story through the experiences of a Brazilian couple, S.P. Luiz and Gis, and the missionary networks that brought them and their two children from São Luís to Kabul in 2003.

The experiences of Luiz and Gis were utterly unique in many ways – they secretly evangelized Muslims in wartime Kabul while running a pizza shop. However, Carranca argues that the couple is also representative of a new era in global Christianity and evangelical missions. In recent decades, as Christianity’s center of gravity has shifted toward the global South, Brazil has become the second-largest source of evangelical mission workers, following only the United States. That the United States still sends out the most missionaries is largely a legacy of the past. Evangelical Christianity’s present – driven by fast-growing Pentecostal forms – is in Latin America, and it is strategists like the Argentinian Luis Bush and workers like the Brazilians Luiz and Gis that are shaping its future.

That future, they hope, lies in the 10/40 Window, especially among its Muslims. As Carranca shows, many mission leaders experienced the September 11 attacks as a sign from God that the long-awaited moment to reach Muslims had arrived. They also sensed the opportunity in a more practical sense. As Luiz’s pastor, Vinci Barros, put it, the attacks “opened the doors into Afghanistan, thanks to the United States” (59). However, the invasions that brought entry into Iraq and Afghanistan – as well as the many American military operations outside of the two countries – made conditions essentially impossible for American and European missionaries who would inevitably be identified with invasion and occupation. Missionary organizations thus turned to the growing pool of workers in the Global South to send into these most dangerous fields.

Evangelizing Muslims is illegal in Afghanistan – it was even so under the U.S.-backed Karzai government. Still, Luiz and Gis built an underground church, performed public (albeit disguised) baptisms at Qargha Lake outside Kabul, and established a school. The simplest of things were dangerous– even moving pamphlets in the trunk of a car – and the dangers only grew as the United States’s state-building project fell apart and the Taliban began retaking control of the country. Not long after Luiz and Gis left Afghanistan to start a new role supporting missionaries throughout the region, Taliban militants murdered their friend and colleague Werner Groenewald and his two children, burning their house to the ground. In 2021, as the Taliban took control of the country altogether, Luis and Gis scrambled to help smuggle dozens of Christian refugees through Pakistan to Brazil.

That was just Afghanistan. Carranca’s reporting follows the lines of the evangelical missionary network throughout the region. She documents Pakistani Christians facing violent backlash after the killing of Bin Laden, Egyptians navigating the hopes and disappointments of the Arab spring, and Syrians and Iraqis facing annihilation at the hands of ISIS. She traces Christians fleeing the chaos among the migrant millions, and eager missionaries sensing opportunity in the upheaval.

The events that frame Soul by Soul will be familiar to any reader interested in the book – they formed much of the international headline news of the last twenty-five years. As much as the work is an investigation of evangelical efforts to reach Muslims, it is even more a retelling of this recent past through the experiences of a vulnerable but determined community of believers. This is where its strength lies – in Carranca’s human reporting, in telling the stories of the kinds of people who take dreams as commands from God and thrust themselves into worlds entirely hostile to their purpose. It is riveting. At times, it is heartbreaking.

If there is a part of the book that could be strengthened, it is in the historical background provided in the prologue. That this material would pose difficulties makes sense. Soul by Soul is first and foremost a work of reporting, not a history book, and it is compelling precisely because its reporting cuts across so many distinct, yet tangled contexts. One of the challenges is thus deciding which historical contexts will most effectively set up the reporting. Carranca chooses to include a long historical background on American Protestant missions in order to set up Soul by Soul’s focus on the shift away from American missionary dominance – it is a historical context focused on who is going into the field.

There is a certain sense to that, but there is also the question of how missionaries go about their work – a major focus of Carranca’s reporting. Here, Soul by Soul would benefit from engaging the longer historical context of Protestant missions in the Islamic world since it touches on patterns that have long been a part of that context: the targeting of minority groups with evangelization (like the Hazaras in Afghanistan), the ambiguous relationship of missionaries to indigenous Christian communities (as in Egypt), and the connections between missions and imperial institutions. This is not to say that Carranca should have included all of this history, but rather that engaging it would raise relevant questions for the work. At the heart of them is this: however different the kinds of workers going into the mission field might be, do they look all that different viewed from the 10/40 Window? Whatever the case, their story is worth telling. Carranca tells it well.