Elders have been set in the Church together with minister for the purpose of the edification of the body and to bring all to a maturity of faith (Eph 4:11-13). Ministers are elders (Titus 1:7, 1 Cor 4:1-2) are called 'the steward of God', particularly stewards of the mysteries of God, who are required to be found faithful.
The elders are to watch over the Church "Take heed therefore unto yourselves, and to all the flock, over which the Holy Ghost hath made you overseers, to feed the church of God, which He hath purchased with His own blood." There is a duty to be strictly attentive, active and cautious in this responsibility [Acts 20:17, 28-31]. The elders must only admit those who publicly profess faith in Christ and who live in conformity to that profession (Titus 1:16, Matthew 7:21). They are like the porters under the Old Testament, (2 Chron. 23:19) 'And he set the porters at the gates of the house of the Lord, that none which was unclean in any thing should enter in'.
Christ has given to these officers the keys of the kingdom (Matt. 16:19; 18:17-18; Jn. 20:21-23; 2 Cor. 2:6-8). "Whatsoever ye shall bind on earth, shall be bound in heaven: and whatsoever ye shall loose on earth, shall be loosed in heaven." [Matt. 18.18], note that this is addressed in the plural (ye, you). The Westminster Confession asserts that elders exercise the keys of the kingdom: “To these officers the keys of the kingdom of heaven are committed, by virtue whereof they have power respectively to retain and remit sins, to shut that kingdom against the impenitent, both by the word and censures; and to open it unto penitent sinners, by the ministry of the gospel, and by absolution from censures, as occasion shall require".
I Cor 5:1-8 shows that the Lord's Supper is the New Testament Passover and that the Church is to purged of the 'leaven' of hypocrisy in order to maintain the true witness and profession of the Church. As they sit at the Lord's table they are to "keep the feast", the feast in the New Testament sense, purely and in sincerity "not with old leaven, neither with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth". Paul condemned them in verse 2 for keeping the man in its fellowship and allowing him to come to the communion table. [1 Cor. 5:2].
With a view to celebrating the Lord’s Supper properly, the Kirk Session at Corinth was to constitute itself into a court of Christ's Church, in the name and by the authority of the Lord Jesus Christ, and "purge out the old leaven", so that they might partake of this holy sacrament in an acceptable manner. "Your glorying is not good. Know ye not that a little leaven leaveneth the whole lump? Purge out therefore the old leaven, that ye may be a new lump, as ye are unleavened. For even Christ our passover is sacrificed for us:" [1 Corinthians 5:6-7]. Other relevant portions are:
2 Cor. 10. 8. "Our authority which the Lord hath given us for edification".
1 Thess 5. 21. "Prove all things: Hold fast that which is good."
If the elders have received the keys from Christ they must be very careful to open the door of admission only to those whom Christ would have them admit. They are to look for an accredited profession of faith. There are three dimensions to Christian profession: doctrine, duty and experience. These dimensions are also necessary to communion with Christ JN 14:21 "He that hath my commandments [doctrine], and keepeth them [duty], he it is that loveth me: and he that loveth me shall be loved of my Father, and I will love him, and will manifest myself to him [experience]." These are those "that join themselves to the LORD, to serve him, and to love the name of the LORD" IS56:6. This faith, love and obedience needs to be tested in an objective manner however, if a court of the church is to admit individuals to the privilege of this sacrament. They cannot, however, know the secret state of anyone's soul and they can only assess the evidence of the outward profession and consistent conduct of the person applying to be received as a communicant (Acts 19:18).
Why do sessions interview candidates and not just issue a verbal warning from the pulpit?
[1] Reliance on the word of warning from the pulpit alone fails because it introduces a more stringent standard for admission to baptism than the Lord's Supper. Before a person is allowed to present himself, or his children, for baptism, he must satisfy the Session as to his profession and life. If there is only a verbal warning in the case of the Lord's Supper, however, the candidate is only asked to examine himself before he is allowed to come to the Lord’s Table - this is inconsistent.
[2] If we rely upon a word of warning from the pulpit alone, we are dangerously assuming sufficient competence to judge spiritual matters on the part of those who may be complete strangers. Sessions must assume the opposite, unless-and until-they have obtained adequate information. Many people who say that they are Christians are profoundly ignorant of what that really means.
[3] A mere verbal warning does not deal with the problem of those who are under discipline from other churches if it is left up to the individual to judge his own case. It does not do justice to the sinful propensities of men, or to the seriousness of church censures.
[4] There is such a thing as corporate responsibility. Many people belong to Churches that will not submit to the Word of God but rather reject it. There are also Churches that do not administer the sacraments as appointed by Christ in His Word, but add to and take from them. They do not emphasise the need for holy living according to the Word of God. These individuals think that this has nothing to do with their own personal faith. This needs to be vitally addressed. Only examination by elders will achieve this.
[5] People need their errors pointed out - it is no kindness to ignore them.
[6] In the best days of the Church admission to the table was viewed as proper only when the elders had sufficient knowledge of the communicants to judge them to be worthy receivers. If persons are admitted of whom the Session know nothing it cannot be reconciled with the clearly stated requirement of the Westminster Confession which says:
...ignorant and ungodly persons, as they are unfit to enjoy communion with [Christ], so are they unworthy of the Lord’s table; and cannot, without great sin against Christ, while they remain such, partake of these holy mysteries, or be admitted thereunto. [Note that people must be admitted they cannot admit themselves]
Larger Catechism Answer [WLC 173] 'May any who profess the faith, and desire to come to the Lord's supper, be kept from it?'
'Such as are found to be ignorant or scandalous, notwithstanding their profession of the faith, and desire to come to the Lord's Supper, may and ought to be kept from that sacrament, by the power which Christ has left in his church, until they receive instruction, and manifest their reformation'.
[7] Examination by the elders means that people are brought to face the seriousness of what it means to partake of the Lord’s table.
[8] The table was fenced in this way in the Early Church:
Justin [c.150 AD]:
And this food is called among us [the Eucharist], of which no one is allowed to partake but the man who believes that the things which we teach are true, and who has been washed with the washing that is for the remission of sins, and unto regeneration, and who is so living as Christ has enjoined. [Apology I
The requirements of the church of 150 AD were 1] believe the teachings of the church [2] baptism and [3] godly life. The Didache Didache
[9] It was also fenced from the Reformation onwards. Knox's Book of Common Order, adopted in Scotland in 1564: "The administration of the Table ought never to be without examination pass before, especially of those whose knowledge is suspect. We think that none are apt to be admitted to that Mystery, who cannot formally say the Lord's Prayer, The Articles of the Belief, and declare the sum of the Law." Knox goes on to say: "And therefore of necessity we judge it, that every year at least, public examination be had by the Ministers and Elders of the knowledge of every person within the church; to wit, that every master and mistress of household come to maturity, before the Ministers and Elders, to give confession of their faith, and to answer such chief points of Religion as the Ministers shall demand"
[10] As in all things in the Church, cursed be he that doeth the work of the Lord negligently. The elders must not follow convenience but the injunction: "Let all things be done decently and in order" [1 Cor. 14:40].