Satellite television, radio broadcasts, and the Internet present expanding opportunities for Muslims to hear the Gospel.
But how welcoming are churches in Islamic nations to Muslims seeking to know more about Christ?
And what happens when former Muslims start their own fellowships?
"There is so much risk. There is so much danger," Todd Nettleton, director of media development for Voice of the Martyrs, told CBN News.
"They are very concerned about what the government is going to say," he added. "[They think], 'If we are out converting Muslims, that potentially puts a target on our backs from the government.' So, they are very cautious about the idea of converting Muslims, of baptizing Muslims into faith in Christ."
Former Muslim Samer Mohammed agreed.
"Some people are afraid to accept you because they have fear," Mohammed explained. "They think if they accept the Muslim believer, some big problem will come to the church."
Christianity's 'Fourth Branch'
Some Iranian churches allowed Muslim converts to join their congregations, only to discover later that several were actually government spies and Islamists seeking to harm them.
Rejected by traditional Christians, a growing number of Christians from a Muslim background are now seeking to worship in their own way.
Open Doors USA President Carl Moeller called the phenomenon like a "fourth branch" of Christianity.
"Muslims are turning to faith in Jesus Christ, and out of that movement is emerging an entirely new way of expressing Christianity within the context of the Middle Eastern culture," he said.
Samer Mohammed is a Palestinian Muslim background believer, or "MBB" as they are sometimes called. He prefers to fellowship with others like him.
"We understand each other. The Muslim believers meet together, worship together, and this is good for these people," Mohammed said.
"If I invite [a former Muslim] to MBB communities ... it's easy for him," he added.
But, these communities are also at risk of misunderstanding important Christian doctrines.
"Many of them -- because God's word is difficult to get ahold of -- find it easy to be misled and led astray by those who develop heretical or abhorrent theological practices," Moeller said.
"Because there is no Bible to counteract that presence in the congregation, it can go on for quite some time," he added.
Former Muslim Rachid is the host of the Christian television talk show "Daring Questions."
He said it's not just a lack of Bibles that is creating heretics.
"Because of lack of training and discipleship and teaching, we can come up with our own ideas or comfort zones," Rachid said. "Where we can please our former faith and our new faith, and come up with a new mixture of the two faiths."
Some call this growing trend "Chrislam," a blend of Christianity and Islam.
Others refer to it as the "Insider Movement," a practice in which Christians from a Muslim background still attend mosque and perform Islamic rituals.
Mohammed said Christians in the West are advancing the idea. But he rejects the idea.
"For me, I don't want the Muslim people to come in this way to Jesus," he said. "For me, this is still Muslim."
"We are new people in Jesus. No more Islam, no Mohammed, no Koran," he continued. "This [Chrislam] is from Satan for me. This is not from God."
"If a Muslim believes in Jesus Christ and he wants to stay practicing his Islamic faith, it will not work because there are so many pagan rituals in Islam," Rachid said.
"Imagine bringing witchcraft to Christianity and say, 'Let's do both of them' and 'There is no harm.' And we stay Christians while practicing witchcraft. It doesn't work. So, it's the same thing with Islam," he continued.
A Need for Guidance
While he doesn't support the Insider Movement or Chrislam, Nettleton said he can see the value of MBBs attending mosque.
"They're able to lead other people to Christ because they go to the mosque and maybe they strike up a conversation, 'What did you pray for today?'" Nettleton said. "And so they have opportunities."
Rachid is less supporting of the idea.
"If I'm an MBB and I still go to the mosque, what message am I communicating to the Muslims?" he asked. "I'm telling them I'm still a Muslim. I'm not saying to them, 'I've changed. Jesus Christ changed my life. I'm a new person.'"
Rachid said many of his Muslim viewers have embraced the Christian faith because they are not satisfied spiritually.
They are seeking justice and truth, virtues they are not finding in Islam, politics, and revolution.
Mohammed said once Muslims accept Christ, they need help growing in the faith.
"You need to take care of the MBB to give him good discipleship," he said. "Jesus says go and disciple the people."
--Originally aired March 30, 2012.