We believe, since this holy assembly and congregation is the assembly of the redeemed and there is no salvation outside of it,1 that no one ought to withdraw from it, content to be by himself, no matter what his status or standing may be. But all and everyone are obliged to join it and unite with it,2 maintaining the unity of the church. They must submit themselves to its instruction and discipline,3 bend their necks under the yoke of Jesus Christ,4 and serve the edification of the brothers and sisters,5 according to the talents which God has given them as members of the same body.6 To observe this more effectively, it is the duty of all believers, according to the Word of God, to separate from those who do not belong to the church7 and to join this assembly8 wherever God has established it. They should do so even though the rulers and edicts of princes were against it, and death or physical punishment might follow.9 All therefore who draw away from the church or fail to join it act contrary to the ordinance of God.

1Mt 16:18-19  And I also say unto thee, that thou art Peter, and upon this rock I will build my church; and the gates of Hades shall not prevail against it. 19 I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven; and whatsoever thou shalt loose on earth shall be loosed in heaven.

Acts 2:47  praising God, and having favor with all the people. And the Lord added to them day by day those that were saved.

Gal 4:26  But the Jerusalem that is above is free, which is our mother.

Eph 5:25-27  Husbands, love your wives, even as Christ also loved the church, and gave himself up for it; 26 that he might sanctify it, having cleansed it by the washing of water with the word, 27 that he might present the church to himself a glorious church, not having spot or wrinkle or any such thing; but that it should be holy and without blemish.

Heb 2:11-12 For both he that sanctifieth and they that are sanctified are all of one: for which cause he is not ashamed to call them brethren, 12 saying, I will declare thy name unto my brethren, In the midst of the congregation will I sing thy praise.

12:23 to the general assembly and church of the firstborn who are enrolled in heaven, and to God the Judge of all, and to the spirits of just men made perfect,

22 Chron 30:8 Now be ye not stiffnecked, as your fathers were; but yield yourselves unto Jehovah, and enter into his sanctuary, which he hath sanctified for ever, and serve Jehovah your God, that his fierce anger may turn away from you.

Jn 17:21 that they may all be one; even as thou, Father, art in me, and I in thee, that they also may be in us: that the world may believe that thou didst send me.

Col 3:15 And let the peace of Christ rule in your hearts, to the which also ye were called in one body; and be ye thankful.

3Heb 13:17  Obey them that have the rule over you, and submit to them: for they watch in behalf of your souls, as they that shall give account; that they may do this with joy, and not with grief: for this were unprofitable for you.

4Mt 11:28-30  Obey them that have the rule over you, and submit to them: for they watch in behalf of your souls, as they that shall give account; that they may do this with joy, and not with grief: for this were unprofitable for you.

5Eph 4:12  for the perfecting of the saints, unto the work of ministering, unto the building up of the body of Christ:

61 Cor 12:7, 27 7 But to each one is given the manifestation of the Spirit to profit withal.
  27 Now ye are the body of Christ, and severally members thereof.

Eph 4:16  from whom all the body fitly framed and knit together through that which every joint supplieth, according to the working in due measure of each several part, maketh the increase of the body unto the building up of itself in love.

7Num 16:23-26 And Jehovah spake unto Moses, saying, 24 Speak unto the congregation, saying, Get you up from about the tabernacle of Korah, Dathan, and Abiram. 25 And Moses rose up and went unto Dathan and Abiram; and the elders of Israel followed him. 26 And he spake unto the congregation, saying, Depart, I pray you, from the tents of these wicked men, and touch nothing of theirs, lest ye be consumed in all their sins.

Is 52:11-12  Depart ye, depart ye, go ye out from thence, touch no unclean thing; go ye out of the midst of her; cleanse yourselves, ye that bear the vessels of Jehovah. 12 For ye shall not go out in haste, neither shall ye go by flight: for Jehovah will go before you; and the God of Israel will be your rearward.

Acts 2:40  And with many other words he testified, and exhorted them, saying, Save yourselves from this crooked generation.

Rom 16:17  Now I beseech you, brethren, mark them that are causing the divisions and occasions of stumbling, contrary to the doctrine which ye learned: and turn away from them.

Rev 18:4 And I heard another voice from heaven, saying, Come forth, my people, out of her, that ye have no fellowship with her sins, and that ye receive not of her plagues:

8 Ps 122:1 A Song of Ascents; of David. I was glad when they said unto me, Let us go unto the house of Jehovah.

Is 2:3 And many peoples shall go and say, Come ye, and let us go up to the mountain of Jehovah, to the house of the God of Jacob; and he will teach us of his ways, and we will walk in his paths: for out of Zion shall go forth the law, and the word of Jehovah from Jerusalem.

Heb 10:25  not forsaking our own assembling together, as the custom of some is, but exhorting one another; and so much the more, as ye see the day drawing nigh.

9Acts 4:19-20 But Peter and John answered and said unto them, Whether it is right in the sight of God to hearken unto you rather than unto God, judge ye: 20 for we cannot but speak the things which we saw and heard.