A church is a building in which worship, usually of a Christian nature, takes place.
Sometimes the term "Church" is used to refer to a collective Christian body such as the Catholic Church or the total body of believers.
The word "Church" arises in Christian use from a number of New |Testament sources, perhaps the prime, the words of Jesus - "On this rock I will build by Church". This is at once concrete and it is general with portents of the future. It is concrete as Church, the "Ekkelsia" those that are "called out" (of the environs) for the purpose of gathering together is a direct reference to the synagogue ("led or assembled togther") - "Beit Knesset" in Hebrew, those that are "gathered together", visible, concrete, societal, a people. These then, together are the Israel of God, a new creation, upon which will sit, guide, judge, the 12 apostles, waiting for the Lord to return.
And yet, Church, is something beyond this, something that takes it in but transcends this as Church is somehow related to the Body of the Risen Christ which He now in Heaven fills and lives in here on earth. We the Church have now somehow by His grace become part of His Body, or we ,all together, are His Body on earth, through which He lives and continues His good and continuing work of the Kingdom of God.
Our nexus to His Body are the following ; it is faith in Him our Savior that has initially brought us to the Body to join us togther with a real community and to Him. It is baptism which has brought us firmly into the life of the Spirit of the Body and Community and signifying that it is to Him that we belong. It is the communion with Him granted us at the table of the Lord in "Communion" that strengthens us for our life here on earth. It is the illumination and actual grace to help that comes to us in the hearing of His Word of Holy Scripture. It is in obeying that Word which we have heard that these weak and mortal bodies on earth receive Heaven's transforming power and new life - even as we live on earth awaiting His return, and it is in forgiving love, one member of the Body to another, that we actually experience the sweetness of Jesus living with us in His Body on earth, the Church.
The Church is thus concrete and specific, the people of God among many peoples, and transcending this, it is general, universal, attached to a greater reality - the Risen Christ Himself. The joining of Christ in Heaven with His Body on Earth, the Church gives force to this saying of the Lord:
"Then shall the King say unto them at his right hand, Come, ye blessed of my Father, inherit the kingdom prepared for you from the foundation of the world; for I was an hungred,and ye gave me meat: I was thirsty, and ye gave me drink: I was a stranger, and ye took me in:Naked, and ye clothed me: Sick. and visited me: Then shall the righteous answer him, saying, Lord ,when saw we thee an hungred and fed thee? or thirsty, and gave thee drink? When saw we thee a stranger and took thee in? or naked and clothed thee? or when saw we thee sick or in or in prison, and came unto thee? And the King shall answer, and say unto them, inasmuch as ye have done it unto one of the least of these, my brethren, ye have done it unto me. =Matt. 25:35-40
Possibly the first Church Structure
On Mount Zion in Jerusalem, identified wrongly as such by the Crusaders, close to the present day Roman Catholic Dormition Abbey, and entering the room below that of the Last Supper of Jesus, one views the huge remembrance stone indicating the tomb of King David from Crusader times. Outside the tomb enclosure, there are are usually orthodox Jews praying. But behind the remembrance stone on the wall of the room facing the Temple Mount, one can see the niche at the exact height above the ground for the scrolls of the Bible to be placed. This indicates that the room had originally been a synagogue. Walking around the outside of the room in the courtyard, one can see the "Herodian" stone blocks with their characteristic and tell-tale incised borders. So this room was originally built in the first century. Further, the stones were of different sizes and shapes indicating that this was their secondary placement having been brought here from elsewhere, perhaps the destroyed temple area itself. During the 1948 Israeli War of Independence, an artillery shell landed in the courtyard, shattering the successive layers of plaster of the room within, until the last layer could be seen, extending down past the Ottoman Turk, Early Muslim, Crusader, Byzantine period floor levels, ending at the original 1st century floor. This was further confirmation that the room was built in the first century. There were prayers in Greek to Jesus inscribed on the wall. This indicates that the synagogue was a hellenistic oriented Jewish Christian synagogue (similar to the New Testament reference of the Jewish "synagogue of the Libertins"). It also explains why the room, right across the valley from the Temple Mount, was not oriented to it in the usual way that the worshippers would face the temple, but was rather facing north in the exact direction of the both the later "Constantinian" Church of the Holy Sepulchre and the most recent "Gordon's Calvary" - the two contenders for the site of the crucifixtion, burial and resurrection of Jesus.
This "Kibla" or prayer direction is in accord with ancient practice of facing the direction of importance. For the Old Testament and Judaism, facing Jerusalem and, in particular if within Jeruselem, facing the temple; for Islam (after it disavowed Jerusalem as the kibla), facing Mecca; and, at one time, for Christians, facing the East, the direction of the rising sun (Mal.3) and also the direction from which Christ would return.
The mosaic Byzantine Madaba map of Jerusalem shows the location and the room as being adjacent to another structure - the Church of the Holy Apostles, indicating that it was considered as particularly important or held holy in the Byzantine period. The later huge Crusader period Church of St. Mary, built at the same spot as the earlier Byzantine church, is shown by archeology to have actually included the room within the Church structure. This then was the most likely first Church and home to the Believers in Jesus before the destruction of Jerusalem in 70 A.D. The "Church House", possibly the home of Mark, that would later be called "The Church of the Holy Apostles" and the "Mother of all Churches" - (The Liturgy of St. James).
The word church comes, through the Old English circe, from the Koine Greek κυριακον (kyriakon), which means "Lord's House".