There is a group of
Muslims in a city in the state of Georgia, USA, who want to establish a mosque for holding
the five daily prayers and Jumu’ah prayers, and there was a church up for sale. Is it
permissible for them to buy this church and turn it into a mosque after they remove the
crosses and images that are hanging or are engraved in it?

Praise be to Allaah.

Yes, it is permissible to buy it and make it into a mosque, but they
have to remove all the crosses and images that are hanging or engraved in it, and
everything that indicates that it is a church. We know no reason why this should not be
allowed.
From Fataawa al-Lajnah al-Daa’imah, 6/267.

Among the evidence that it is permissible to turn the places of worship
of shirk and kufr into mosques is the following hadeeth: From Talq ibn ‘Ali (may
Allaah be pleased with him): “We went out as a delegation to the Prophet
(peace
and blessings of Allaah be upon him). We gave bay’ah (oath of allegiance) to him and
prayed with him. We told him that in our land we had a place of worship [the word used
indicates a Jewish or Christian place of worship], and we asked him to give us some of the
water left over from his wudoo’, so he called for water and did wudoo’ and
rinsed out his mouth, then he poured that water into a vessel and told us, ‘Go, and
when you reach your land, knock down that place of worship and sprinkle this water over
the place, then use that place as a mosque.’ We said, ‘Our land is far away and
the heat is intense, the water will dry up.’ He said, ‘Add more water to it, it
will only increase it in goodness.’ So we set out and when we reached our land, we
knocked down our place of worship, sprinkled water on the place and used it as a mosque.
We called the adhaan there, and when the monk, a man from Tayyi’, heard it, he said,
‘The call of truth!’ then he climbed one of our hills and we never saw him
again.” (Reported by al-Nasaa’i, 694). And Allaah knows best.

The building itself does not need to be destroyed so long as its roof,
walls etc. can be put to use and architectural alterations can be made, after removing all
the symbols of Shirk and other forbidden things, so that the structure of the building
will match the rows of prayer, facing the direction of the Ka’bah. Allaah is the
source of strength and He knows best.