Several churches across Europe have reported an unprecedented number of Muslim refugees seeking Christian baptisms.

This comes as Europe has seen mass migrations, easily surpassing the one-million-mark in 2015 alone. The new arrivals have raised fears and challenges across the continent.

The congregation of a Berlin suburb has grown from 150 two years ago to almost 700, due mainly to Muslim converts, The Guardian quoted the Steglitz Lutheran Trinity church’s pastor as saying.

Meanwhile, the Austrian Catholic church logged 300 applications for adult baptism in the first three months of 2016. Around 70% of converts are estimated to be refugees.

In the Netherlands and Denmark, many were converting from Islam to Christianity, said the Daily Beast, while a survey of Christian baptisms among the new immigrants in Finland documented at least 225 baptisms from Islam.

With conversions drawing on different motives, baptism classes can sometimes take several months, offering ample time before confirmation.

“When we do confirmations, we work hard to make sure the person is serious.” said Toby Howarth, the Anglican Bishop of Bradford, in the UK.

“We all have mixed motives. But if someone says ‘I believe this’, who are we to “make windows into people’s souls”?

“The only thing I can do is see if people are still there a year later – and often they are.” added Howarth, who himself conducts confirmations where one in four over the past year were of converts from Islam.