They knew it would take a miracle to get them out of Evin Prison, Iran's most notorious prison. And it did.

After just a little more than four months of confinement, three Christian missionaries from the neighbouring country of Azerbaijan walked out of one of the worst prisons in the world on Nov. 6, 2016 after they were charged with trying to convert Iranians to Christianity, a serious offence that usually carries a 10-year jail sentence.

In their first television interview hours after being released, the three men—Bahram Nasibov, Eldar Gurbanov and Yusif Farhadov—told CBN News they knew their mission into Iran was dangerous.

"We were expecting God to do something new for us on this trip, but we had no idea of the events that would transpire hours after we arrived," said Nasibov.

They left the Azerbaijani capital city of Baku, crossed the Iranian border and headed to Tehran where they were to meet secretly with a group of Iranian Christians on June 24, 2016.

They were in an apartment leading a Bible study when Iranian agents barged in, catching them by surprise.

They were subsequently charged and sent to Evin Prison where they spent two months mostly in solitary confinement in a tiny, cold room, with no windows, no bed and just a sink, they told CBN News.

Nasibov said despite the hardship they endured, he for one "never regretted going to Iran."

He said this was because of a conversation he had with God in 2003. "He [God] asked 'Whom shall I send to the nations?' And I said, 'Here am I, send me'," Nasibov answered. "Since then I've tried not to miss an opportunity to go and preach the Gospel in other countries."

For his part, Farhadov said he had already foreseen in a dream what would happen to them in Iran before they left their native Azerbaijan.

"But as I sat in my prison cell, God reminded me of that dream but also gave me a promise from Psalm 2 that He will make the nations our inheritance. That gave me hope and strength to endure," he said.

The three Christians said they never lost hope while in prison as they spent their days and nights praying and singing aloud Christian songs like "How Great Is Our God."

Alexander Neretin, a Russian pastor, started campaigning for the men's release right after their arrest. Churches across Azerbaijan and in neighbouring countries joined in the effort to help the three Christian men regain their freedom.

Surprisingly, in what Neretin said was nothing short of a miracle, Iranian authorities decided to release the three Christians upon payment of bail amounting to $85,000.

Neretin then flew to Iran carrying the bail money. Days later, Nasibov, Gurbanov and Farhadov, returned home to Azerbaijan as free men.