The New Testament speaks of a large church in Jerusalem meeting together in a public space
(e.g., the outer court of the temple in Acts 2:46)
and in smaller groups in houses
(e.g., the house of Mary, mother of Mark, in Acts 12:12).
This practice must have been carried on
in many cities of the Roman empire.
For the most part, the church was dependent
on members or supporters (patrons) who owned larger houses, providing a place for meeting.
In Rome, there are indications that early Christians met in other public spaces such as warehouses or apartment buildings.
Even when there were several meeting sites in a city,
the Christians had the sense of being one church.
They maintained unity through organisation
(from the second century on,
beginning at different times in different places,
one bishop in a city became the centre of unity
for orthodox Christians there) and symbolic gestures
(in Rome, the eucharistic bread was sent
from the bishop's church to other assemblies).
Before Emperor Constantine recognized Christianity
as a legal religion in 313,
corporate ownership of property by the church
could be legally ambiguous.
It seems that the first property
owned by the Roman church were the catacombs.
These were not places of meeting, however, but burial sites.
The early Christians were small in number
and often persecuted,
so they couldn’t build special buildings for their own use.
Instead, they used whatever buildings were available to them when they came together–private homes,
public halls, even synagogues
(for many of the earliest Christians were also Jewish).
Only later, as they grew in number,
did they have the ability and the legal right
to build separate church buildings.
In time, some of these became very elaborate
(and you can still see many of these
ancient cathedrals in Europe today).
As Christians grew in number, they also occasionally took over buildings that had once been pagan temples,
some of which were quite large.
The Bible says,
“So whether you eat or drink or whatever you do, do it all for the glory of God”
(1 Corinthians 10:31).