Over 80 Muslim refugees from Iran and Afghanistan have converted to Christianity and were baptised on Thursday in Hamburg, Germany.

"The motive for the change of faith is the same for many: they are disappointed with Islam," Albert Babajan, the pastor who conducted the mass baptism, told German magazine Stern.

One Iranian refugee, Shima, told Stern how Islam had never brought her freedom, rather she had lived under constant fear of sin.

"I've been looking all my life for peace and happiness, but in Islam, I have not found it," she said.

"To be a Christian means happiness to me."

Another Iranian refugee, Solmaz, said: "In Islam, we always lived in fear. Fear God, fear of sin, fear of punishment. However, Christ is a God of love."

The ceremony was conducted in the Hamburg city park, and the converts wore white robes, before being baptised in the lake.

Conversions to Christianity among the refugee population in Germany is not uncommon. Babajan has baptised 196 Muslims in 2016 and reportedly expects this number to grow to 500 by the end of the year.

There has been some suspicion as to the true motive behind those seeking asylum's conversions to Christianity.

Germany immigration authorities give priority to Christian refugees, as they would face prosecution and even death if they returned to their native countries.

In both Iran and Afghanistan, apostates face the death penalty.

"If I have the impression that someone does not believe from the heart, then I do not baptise them," said Babajan.

Rather than asking for memorised scripture, Babajan asks people how their lives have changed.

"Because the Christian faith changed the way of thinking, the world view. If someone told me that at night he can sleep again or an old enemy could forgive, then I know that in his heart he is a Christian."

Babajan has declined baptism to many who he suspected of mal-intent.

"There are maybe 20 or 30 per cent who really want to hear the gospel. For those who want to have a license, I must face the door... It is very easy, whoever does not believe will not be baptised," he told Stern.