In Christianity, ministry is an activity carried out by Christians to express or spread their faith, the prototype being the Great Commission. 2003's Encyclopedia of Christianity defines it as "carrying forth Christ's mission in the world", indicating that it is "conferred on each Christian in baptism." It is performed by all Christians. This is distinguished from the "office of minister", to which specific individuals feel a certain vocation. It can signify this activity as a whole, or specific activities, or organizations within a church dedicated to specific activities. Some ministries are identified formally as such, and some are not; some ministry is directed towards members of the church, and some towards non-members. See also Apostolates.

In Christian churches, a minister is someone who is authorized by a church or religious organization to perform functions such as teaching of beliefs; leading services such as weddings, baptisms or funerals; or otherwise providing spiritual guidance to the community. The term is taken from Latin minister "servant, attendant", which itself was derived from minus "less".