The Islamic State (IS) has executed thousands of people during their campaign to establish an extremist Sunni Muslim reign, but a Middle East expert says they are failing in their goal.

Tom Doyle of international mission organisation e3 Partners said that the terrorists' tactics have actually caused people to turn away from Islam.

"They decide to be the most outrageous, in-your-face terrorist group of all time, and they've accomplished that," Doyle admitted. "But I think, in many ways, this has back-fired on them.

"[ISIS violence] in a sense, is just sending shock waves through Islam, as people are really rethinking their whole theology."

Doyle reported that more Muslims have converted to Christianity in the past ten years than in the past 14 centuries.

"Crucifixions, beheadings at the hands of ISIS [are] is turning people away," he explained. "Recently, they've had gatherings [that] total over 1,000 people that are fed up with Islam and are searching for something different.

"It doesn't take a genius to figure out [that] if you're Muslim [and] you don't follow Islam according to their teaching, or if you don't get behind the caliphate, [death is] the same fate that you're going to realise."

Thousands of religious minorities in Iraq and Syria have been persecuted, raped, and killed by the militants in the three years since the US withdrew from the region.

The British-based Syrian Observatory for Human Rights recently reported that IS has killed 1,878 people in Syria over the past six months, including 1,175 civilians.

Christians in cities such as Raqqa, Syria have been driven from their homes, and those that remain are unable to leave the city due to their age, health, or lack of resources. The persecuted citizens leave their homes for only a few hours each morning, and face the threat of death daily.

"The executions are a little bit less now, because there are fewer people to be executed," a Raqqa resident using the alias Abo Ward Al-Raqqawi told Radio Free Europe Radio Liberty last month. "But last Friday they executed two people here in the public square."

Middle East missions and donation opportunities are available through e3 Partners' website.