From The Art and Popular Culture Encyclopedia
A church building is a building or structure whose primary purpose is to facilitate the meeting of a church. Originally, Christians met in synagogues and in one another's homes. As Christianity grew and became more accepted by governments, rooms, and eventually entire buildings, were set aside for the explicit purpose of Christian worship.
Traditional church buildings are often in the shape of a cross, and frequently have a tower or dome. More modern church buildings have a variety of architectural styles and layouts; many buildings that were designed for other purposes have now been converted for church use, and similarly many original church buildings have been put to other uses.