Sectarianism is carnal
[1Co 3:1-23 NKJV] 1 And I, brethren, could not speak to you as to spiritual [people] but as to carnal, as to babes in Christ. 2 I fed you with milk and not with solid food; for until now you were not able [to receive it], and even now you are still not able; 3 for you are still carnal. For where [there are] envy, strife, and divisions among you, are you not carnal and behaving like [mere] men? 4 For when one says, "I am of Paul," and another, "I [am] of Apollos," are you not carnal?
Watering, working, warning
5 Who then is Paul, and who [is] Apollos, but ministers through whom you believed, as the Lord gave to each one? 6 I planted, Apollos watered, but God gave the increase. 7 So then neither he who plants is anything, nor he who waters, but God who gives the increase. 8 Now he who plants and he who waters are one, and each one will receive his own reward according to his own labor. 9 For we are God's fellow workers; you are God's field, [you are] God's building. 10 According to the grace of God which was given to me, as a wise master builder I have laid the foundation, and another builds on it. But let each one take heed how he builds on it. 11 For no other foundation can anyone lay than that which is laid, which is Jesus Christ. 12 Now if anyone builds on this foundation [with] gold, silver, precious stones, wood, hay, straw, 13 each one's work will become clear; for the Day will declare it, because it will be revealed by fire; and the fire will test each one's work, of what sort it is. 14 If anyone's work which he has built on [it] endures, he will receive a reward. 15 If anyone's work is burned, he will suffer loss; but he himself will be saved, yet so as through fire. 16 Do you not know that you are the temple of God and [that] the Spirit of God dwells in you? 17 If anyone defiles the temple of God, God will destroy him. For the temple of God is holy, which [temple] you are.
Avoid worldly wisdom
18 Let no one deceive himself. If anyone among you seems to be wise in this age, let him become a fool that he may become wise. 19 For the wisdom of this world is foolishness with God. For it is written, "He catches the wise in their [own] craftiness"; 20 and again, "The LORD knows the thoughts of the wise, that they are futile." 21 Therefore let no one boast in men. For all things are yours: 22 whether Paul or Apollos or Cephas, or the world or life or death, or things present or things to come--all are yours. 23 And you [are] Christ's, and Christ [is] God's.