A few days ago, just miles from war-torn Mosul as the battle to retake the city rages on, Christians gathered together in prayer. With ISIS less than 100km away, they sang, wept, and worshipped God. People of all different denominations and creeds, united in their desire for peace.

The group were led by a team from Burn 24-7, a US-based organisation that grew out of a college movement, and is headed up by Seun Feucht and his wife Kate. They have links to Bethel Church in Redding, California, and send out teams all over the world to share the love of Jesus through worship.

Each team holds regular 'burns' – prayer and worship events – that can last anything from 12 to 100 hours. "We try and have them consistently hosted in a city once a month, and the heart is to gather Christians of different backgrounds and different denominations, to come together and take the time to worship and exalt God in their city," says Kelsie, who works with Burn 25-7 in Kurdistan.

"It's missional, too – it's not just to worship and pray but from that place we have teams going out to evangelise and share the love of Jesus, [and] heal the sick," she told Christian Today. "The heart is seeing people ignited with a first love for Jesus, to gather together in unity to see his presence established in a place."

Of course that's easier done in some places than others. Burn 24-7 has teams and prayer centres all across the US, but also around the world. Short-term teams are placed in Mozambique, Democratic Republic of Congo, Paraguay, China and Russia; some of the most difficult countries in the world for Christians to live out their faith, either because of government opression or vigilante groups. Kelsie and her team have been working in Kurdistan – an autonomous region of Iraq – since the beginning of this year, serving displaced people forced to flee their homes as ISIS advanced.

"Our hearts began to burn for what was going on here," Kelsie says of 2014, when Islamic State militants overran the Nineveh Plain in Northern Iraq, slaughtering thousands and taking women and children captive. She and a couple of others felt "the need for hope" in Iraq, and began making arrangements to move there. "In 2015, a small team came here with the basic, simple goal of worship, prayer, and loving whoever God put in front of us," she says. "From there, we saw the need for those people to be shown the love of Jesus, and it felt like an open-window time, so we responded, and it was that simple – a simple 'yes'."

Kelsie moved over in January this year as part of the 'Light a candle' project, and she and her colleagues partner with a local House of Prayer, where they hold 'burns' once a month. These usually involve 12 hours of constant worship and prayer with local believers – singing and crying out to God in English, Kurdish, Arabic and Farsi.

Their latest 100-hour gathering, though, was different. It's the second of its magnitude the team has held in Kurdistan. Last year, they gathered workers from Jordan, local Arabs and Kurds, Iranians, Americans, Brits and Canadians. During monthly 'burns', they've ended up actually praying for ISIS militants – the very people that forced many of those in the room to flee their homes and communities.

"It's one thing to pray from afar for ISIS, and another to pray here, where we're 80km from the city [Mosul] with people and believers who have lost everything. Who have fled from a people group which is blatantly wanting to destroy them, and they are still praying for their salvation and for the mercy of God: that he would show up to these militants," Kelsie says. "That is quite powerful. Every time we pray for ISIS it's a powerful time. To see people who have lost everything as a result of ISIS, praying for them, is a beautiful thing."