The Lord's Supper

 The Lord Jesus declared in I Cor 11:24-26 (NASB)

²⁴ and when He had given thanks, He broke it and said, “This is My body, which is for you; do this in remembrance of Me.” ²⁵ In the same way He took the cup also after supper, saying, “This cup is the new covenant in My blood; do this, as often as you drink it, in remembrance of Me.” ²⁶ For as often as you eat this bread and drink the cup, you proclaim the Lord’s death until He comes.

The Lord's Supper is a commemorative ordinance to be observed by the Scriptural Church in memory of the Savior whose body was broken and whose blood was shed on our behalf (1 Cor 11:24).

Only baptized believers have a right to partake of the Lord's Supper. The Great Commission of Our Lord in Matthew 28:18-20 commands that the new disciples be baptized and then be taught to observe all things that Christ has commanded His disciples. And one important thing the Lord had commanded was the partaking of His Memorial Supper. To partake of the Lord's Supper before baptism is to disobey this God-given order. And if we encourage anyone to violate the Lord's instruction on this matter we shall be partakers of their sin. It is a sin to invite unbaptized people to partake of the Lord's Supper.

In Acts 2:41-42 (NKJV), please note the order:

1. gladly received His Word -Disciples
2. were baptized - Baptized disciples
3. that day... were added to them- Church members
4. continued steadfastly in the apostles' doctrine - Sound in faith
5. and fellowship - United in love and faith
6. breaking of bread, and in prayers - Partaking of the the Lord's Supper

This is the divine order: Close Communion.

By close, I mean participants must be those who have experienced the believers' baptism. And the invitation is made by the celebrant specifying this condition for participation + self-examination (1 Cor 11:27-34). 

Everything must be done with a pure heart in solemn remembrance of the precious Lord Jesus Christ. It is most important that the partakers of the Holy Communion be regenerated Christians (I Cor 10:14-21; 11:23-26) and who are walking truly in love of God and one another as the Lord commanded during His Last Supper (John 13:34-35). They must not be in disunity (I Cor 11:18-22; John 17:20-23) and guilty of sin as they run the terrible risk of being judged by the Almighty God (I Cor 11:27-34). This could be fatal. Thus, it is so important to self-examine oneself carefully before partaking of the Holy Communion with other believers.

We are to teach the truth of the Word of God, to admonish, to exhort, to warn one another-all in love, but it is Our Sovereign Holy God who is the final Righteous Judge of a person's real inner heart and spiritual condition though.