In Christianity, ministry is an activity carried out by Christians to express or spread their faith, the prototype being the Great Commission. The 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 most Christians. This is distinguished from the "office of minister", to which specific individuals who 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. Age-specific ministry As churches attempt to meet the needs of their congregations, they often separate their members into groups according to age categories. Age-specific groups meet for religious study including Sunday school programs, fellowship, and other activities. These age divisions may include: Nursery Pre-school Children, generally elementary age students Youth, generally middle and high school students Young Adults, designed for university-age students Adults, which is often broken up into single adults, couples ministry, men's and women's ministries, and senior adults. Advantages and disadvantages There are several advantages to the concept of age-specific ministries. Many parents / caregivers are glad to allow the church to be in charge of the spiritual enrichment of their children. Similarly, they are used to using programs for the development of their children such as weekday childcare, preschool, and grade school and enjoy the ability to continue a similar format in church. These ministries allow churches to provide 'age-appropriate' activities and content to maximize spiritual education and growth as well as peer group fellowship. Ministries often provide fellowship activities outside of the church service that encourage the involvement of non-church going friends and relatives. Age-specific ministry does have certain disadvantages, mostly stemming from the separation of children from the primary church functions. In terms of religious education, the 'socialization' of children into the faith community is one important approach that requires connecting the children and family with the wider congregation. These ministries may increase the possibility of child abuse within the church as it does increase the amount of time children spend without the supervision of their particular parent or caretaker or the presence of the congregation at large. It is worth noting, however, that many churches hire certified teachers