The word denotes both a church building and the Christian community, local or universal. The origins of the Church as a sect within 1st-cent. Judaism lie in the Lord's choice of twelve disciples (called Apostles). Their mission was initially to Israel, but soon after the Resurrection Gentiles began to join the Greek-speaking Jewish Christians. St Paul's Gentile mission laid the foundations for the Gentile Christianity which became dominant after the fall of Jerusalem in 70 and the expulsion of Jewish Christians from synagogues in the 80s. From the outset the Church never considered itself a voluntary organization; it constituted the faithful remnant of God's people who had recognized the coming of the Messiah and it soon understood its mission in universal terms. After the deaths of St James (the Great), St Peter and Paul in the 60s, and the marginalization of Jewish Christianity, new structures were developed. The essence of the Church was later epitomized in the traditional ‘notes of the Church’, namely unity, holiness, catholicity, and apostolicity. As teaching the Apostles' doctrine and historically descended from them, the Church is apostolic. Its membership, its orders of ministers, and its unity are established by participation in visible sacraments, i.e. those of Baptism and Confirmation, of Holy Orders, and of the Eucharist, respectively. After the split between the E. and W., the RC and E. Orthodox Church each maintained the other was in schism (q.v.) and that itself was the historical manifestation of the visible Church. In addition to the visible Church on earth, there exists the invisible Church of the faithful departed.
The Reformation led to a reformulation of the idea of the Church. It sought to proclaim its being in terms of the Word of God rather than in sacramental relationships. Among Protestants, two doctrines gained wide acceptance: