The Church, which is uncreated and eternal, is both invisible and visible. It consists of those who are on earth, 'fighting the good fight', and those who are in Heaven experiencing the triumph of the glory of God. The Church, as the Body of Christ is the dwelling place of the uncreated glory of God - and we cannot separate Christ from the Church, nor the Church from Christ. This is why the Church is vital for our salvation - or to put it simply, outside of the Church, there is no salvation.
The ancient Orthodox teaching, is that Christ Himself is indeed entirely and fully present in each local church, with all its members. Therefore, when we celebrate the Eucharist, the entire Church ( Christ Himself, with His Saints, and all the faithful of the world ) is present. Furthermore, when we as individuals partake of the Holy Communion, we receive inside us the whole Christ. During the Divine Liturgy, the entire Church becomes present, and becomes one - a communion under the Almighty God. It is for this reason that the church of a monastery is called the 'katholikon', the place of the whole Church.
The Church, as joy, has been victorious through history, and it is through this proclamation, and witness of true joy that Christianity becomes comprehensible, and flourishes. The Gospel of Luke, begins and ends with this great joy : 'I bring you good tidings of great joy' ( Lk 2:10) , 'And they worshipped Him and returned to Jerusalem with great joy' ( Lk 24:52 ). Within the Body of Christ, the Church, we are given the opportunity to partake of this joy, and 'enter..into the joy of thy Lord.' ( Mt 25:21 ) We have no other means of entering into this joy, except through one action that is both the fulfilment and source of joy - the Eucharist.
The Divine Liturgy, or Eucharistic celebration, is the 'Journey to the Kingdom' as Fr Vassilios Papavassiliou puts it, or 'the journey of the Church into the dimension of the Kingdom' as Alexander Schmemann writes. This journey begins from the minute we decide to attend the Liturgy, and leave our homes and 'worldly cares.' It begins when we all, whites, blacks, rich and poor, come together - constituting what it means to be a Church - a communion under Christ. The Liturgy separates us from the world, and all its worries and controversies - and we become one body - the body of Christ. The Eucharistic Liturgy is not of this world - it is a conversion to another reality. Even when the Lord Himself appeared to His disciples, it was no longer sufficient to simply know that He was the Christ, the Son of God - as He is not a part of 'our' world, but rather He gives us the opportunity to be a part of His ! His disciples did not know Him through His physical appearance, as He was unrecognisable - but through entering into a communion with Him. It is only through the mysteries of His Church - and of course in particular through partaking of His Holy body and blood that we know Christ, and can obtain a relationship with Him. As Fr Alexander Schmemann writes 'the early Christians realised that in order to become the temple of the Holy Spirit, they must ascend to heaven where Christ Has ascended' - and we do this in the Liturgy of the Eucharist. We enter into a new life - a life of the Kingdom.
The Eucharist as a Sacramental and Sacrificial Act
The Holy Eucharist is a transforming act - transforming the words of the Gospel, into the very Word of God, and the manifestation of the Kingdom. It is an all-transforming act, involving the whole Church. The offering of the bread and wine is offering the totality of our lives to God - and partaking of the Eucharist, is the our very fulfilment as human beings, as it is a transformation of life and a communion with our Creator and God. Christ offered Himself completely, in total obedience and love - and so this offering that we unworthy servants offer to God, is on behalf of the whole world - it is life. We offer the world and ourselves to God in Christ. Man is a spiritual - and therefore sacrificial being, as love is sacrificial - as it puts the very meaning of life in the other , and gives life to the other; and it is through this that we find true joy and meaning.
Christ, through His sacrifice offered everything that there is to offer to God, and has performed once and for all the Eucharist of life and love. In Him was ( and is ) Life, for all of us - and the Church is all those who have been accepted into the eucharistic life of Christ. We do it in remembrance of Him, as we offer and continuously offer our lives, and the entire world to God. Each time we experience Christ in His Eucharist, we realise that there is nothing else to be offered but Himself, the life and fullness of the world. We bring, and sacrifice ( give to God ) what He has indeed given to us.
When we receive Holy Communion - the Lord's body and blood, it is a restoration of joy and love within us, and indeed a restoration of the entire cosmos. It raises us to Heaven, and to His 'holy and immaterial altar' 'above the heavens' , and is our Divine food. It is the 'door into the Kingdom.' This remembrance and thanksgiving, is Christ's self-offering. The whole point and goal of the Eucharist is to transform and ascend us out of this world, and we are then partakers of the 'joy to come.' It is the Holy Spirit Who manifests the bread as the body and blood of Christ - it is the epiclesis ( invocation of the Holy Spirit ) that performs the transformation. To be in the Spirit, means to be in Heaven, as the Kingdom of God is 'joy and peace in the Holy Spirit'.
Therefore in the Eucharist, 'it is He who seals and confirms our ascension into Heaven, who transforms the Church into the Body of Christ and therefore manifests the elements of our offering as communion in the Holy Spirit.'