The true Church of God is like a building; a single structure, built of many parts, standing upon the foundation of Jesus Christ.
"3:9 For we are labourers together with God: ye are God's husbandry, ye are God's building.
3:10 According to the grace of God which is given unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. But let every man take heed how he buildeth thereupon.
3:11 For other foundation can no man lay than that is laid, which is Jesus Christ." (1 Corinthians 3:9-11 KJV)
"2:18 For through him we both have access by one Spirit unto the Father. 2:19 Now therefore ye are no more strangers and foreigners, but fellowcitizens with the saints, and of the household of God;
2:20 And are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner stone;
2:21 In whom all the building fitly framed together groweth unto an holy temple in the Lord:
2:22 In whom ye also are builded together for an habitation of God through the Spirit" (Ephesians 3:18-22 KJV)
"For we are labourers together with God: ye are God's husbandry, ye are God's building"
Historically, divisions in the true Church were the result of a party (as in a-part and part-ing) spirit - people choosing to follow, in effect, their favorite preacher, rather than Christ. It's a carnal struggle over who is going to take (as in seize) charge of the house in which Christ alone is the Master.
"3:1 And I, brethren, could not speak unto you as unto spiritual, but as unto carnal, even as unto babes in Christ. 3:2 I have fed you with milk, and not with meat: for hitherto ye were not able to bear it, neither yet now are ye able. 3:3 For ye are yet carnal: for whereas there is among you envying, and strife, and divisions, are ye not carnal, and walk as men? 3:4 For while one saith, I am of Paul; and another, I am of Apollos; are ye not carnal?
3:5 Who then is Paul, and who is Apollos, but ministers [Minister means nothing more than a servant] by whom ye believed, even as the Lord gave to every man? 3:6 I have planted, Apollos watered; but God gave the increase. 3:7 So then neither is he that planteth any thing, neither he that watereth; but God that giveth the increase. 3:8 Now he that planteth and he that watereth are one: and every man shall receive his own reward according to his own labour. 3:9 For we are labourers together with God: ye are God's husbandry, ye are God's building.
3:10 According to the grace of God which is given unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. But let every man take heed how he buildeth thereupon. 3:11 For other foundation can no man lay than that is laid, which is Jesus Christ. 3:12 Now if any man build upon this foundation gold, silver, precious stones, wood, hay, stubble; 3:13 Every man's work shall be made manifest: for the day shall declare it, because it shall be revealed by fire [see Baptism Of Fire and When Will You Be Judged?; also Could Christ Return Tonight?]; and the fire shall try every man's work of what sort it is. 3:14 If any man's work abide which he hath built thereupon, he shall receive a reward [see A Reward For Everyone]. 3:15 If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire." (1 Corinthians 3:1-15 KJV)
No one can be a true Christian without The Holy Spirit (see The Cure For The Carnal Mind); thereafter, "3:16 Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you?" (1 Corinthians 3:16 KJV). It's that spiritual Temple that Christ is ultimately building (see Physical and Spiritual Temples).
"3:16 Know ye not that ye are the temple of God, and that the Spirit of God dwelleth in you?
3:17 If any man defile the temple of God, him shall God destroy; for the temple of God is holy, which temple ye are [see also Abomination of Desolation - Where?].
3:18 Let no man deceive himself. If any man among you seemeth to be wise in this world, let him become a fool, that he may be wise. 3:19 For the wisdom of this world is foolishness with God. For it is written, He taketh the wise in their own craftiness. 3:20 And again, The Lord knoweth the thoughts of the wise, that they are vain. 3:21 Therefore let no man glory in men. For all things are yours; 3:22 Whether Paul, or Apollos, or Cephas [i.e. Peter; see Peter's Ministry], or the world, or life, or death, or things present, or things to come; all are yours; 3:23 And ye are Christ's; and Christ is God's." (1 Corinthians 3:16-22 KJV)
Fact Finder: By what measure are the parts of God's building judged to be "upright"?
See The Lord's Plumb Line