The main passages that deal with the Communion are Matthew 26:26-29; 1Cor. 10: 16-22; 11: 23-34.

One of the two ordinances the Lord Jesus gave to the Church is the Observance of the Lord's Table, variously called as "the Breaking of Bread", "Last supper", or "the Holy Communion". It is to be observed continuously- till the Lord comes again: 1cor. 11:26.

The Baptism is the other Ordinance, which signifies the Believer's Union with Christ in His death and resurrction. Romans 6:3-6. It is only once and not repeatable. Eph. 4:5.

The Meaning of Communion:
The word means sharing together, having something in common. It is the partaking of the Body and the Blood of the Lord Jesus Christ which he gave for the salvation of those who believed in Him. It is the fellowship with His Body and His Blood.
The bread and wine represent His Body and His Blood respectively. But they ARE NOT and They DO NOT BECOME His Body and Blood any time!! They remain the symbols and material elements to remind and us of His Body and Blood. Matthew 26:29.
When believers in the local church partake in the bread and wine, they remember the sufferings, and sacrifice of the Lord Jesus on the cross as well as the salvation & redemption He bought by His death on the cross. Matthew 26: 26-29; 1Cor. 11:23-34.
This observance of the Lord's Table, gives testimony to the Oneness of all believers in the Lord Jesus and also maintains the Unity of the local Church. As one bread is broken and one cup is used for all to partake, it speaks of the oneness of God's people.
The very observance proclaims the death of the Lord and His second coming, since His coming again will put an end to this observance.

The Practice of the Communion:
The early church observed the breaking of bread daily from house to house too. It seems, they had the meals together and the Lord's supper was part of their eating together.
Later on, we read in Acts 20:7, they broke bread on the first day of the week. Though Apostle Paul was in that particular place with the local church, they did not break bread. However, they gathered, on the first day of the week to break bread. So it appears, the gathering of the saints on the first day of the week was mainly to remember the Lord by having communion together. All other activities were secondary.
Since it is the Lord's Command, to as often as you do this you remember me" ( 1Cor.11:25),it is imperative on the part of His people to regularly celebrate this holy ordinance to remember and worship the Lord.
It is also a time of and an opportunity to examine one's life at the Lord's Table, in the light of God's word. Since there are warnings against partaking unworthily and hastily. This regular self-examination keeps the believer in the Lord holy and uncontaminated from the pollution and sin in the world. Thus the Holy Communion is an important part of Christ's disciples' lifestyle that helps to maintain the fellowship in the light. 1John 1:7.