The only way to answer that would be to quote verbatim what the scriptures report God as saying on the matter of incorrect theology. Fortunately, there are a couple of particular chapters in the last book of the Bible that do exactly that.
Although the Apostle John wrote this down, what he saw and heard was given directly to him in visions from the risen Christ, which God had given to Christ in the first place. The opening verses of the book of the Revelation make that clear, e.g. "I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty." So, what does this Lord Almighty tell John to write in letters to be sent to seven congregations of Christians dotted around Asia Minor?
The Lord praises the fellowship in Ephesus for exposing evil people, false apostles and the lies they tell. He also knows that they hate the deeds of the Nicolaitans, "which I also hate" (2:2-6). We do not have details of that group, just that they were liars, but the recipients of John's letter would know full well.
Next, he praises Christians in Smyrna for suffering tribulation due to "the blasphemy of them which say they are Jews, and are not, but are the synagogue of Satan" (2:9).
The third 'church' is based in Pergamos but they are warned about tolerating in their midst "them that hold the doctrine of Balaam, who taught Balac to cast a stumbling-block before the children of Israel, to eat things sacrificed to idols, and to commit fornication. So hast thou also them that hold the doctrine of the Nicolaitans, which thing I hate" (2:14-15).
Fourthly, the believers in Thyatira have this against them: "Thou sufferest that woman Jezebel, which calleth herself a prophetess, to teach and seduce my servants to commit fornication" (2:20-23).
The fifth church was located in Sardis and although no specific doctrinal error is identified, they are warned that they are actually spiritually dead. They must repent and "Remember therefore how thou has received and heard, and hold fast, and repent... and watch" (3:1-3). This shows that forgetting how they received God's saving grace, forgetting hearing by the word of faith (Romans 10:8 & 17) can be a spiritually disastrous negligence. They have become lethargic and are no longer watchful. That opens the door wide to incorrect theology and practices.
Sixthly comes the Philadelphian believers who have kept God's word and have not denied his name. They are promised that liars who claim to be Jews but who are of the synagogue of Satan will be made by God to bow before them, and to know God loves them. Also, "Because thou hast kept the word of my patience, I also will keep thee from the hour of temptation, which shall come upon all the world, to try them that dwell upon the earth" (3:9-10).
Lastly comes quite an indictment for the church in Laodicea. God says they are lukewarm, and if that doesn't change, he will spew them out of his mouth. They have succumbed to pride and materialism (3:15-18).
Significantly, God then adds that, "As many as I love, I rebuke and chasten: be zealous therefore, and repent" (3:19). This shows that God desires his people to be alert so as not to tolerate lies, immorality, false teaching, spiritual indolence, pride and materialism. At the end of the first century, those particular churches would know what particular matters God was calling them to attend to. In every century there have been particular snares for God's family, and they all involve lies, immorality, false teaching, spiritual indolence, pride and materialism.
The key to not tolerating them is to remember how we received and heard the gospel of grace, and to be alert to see where any deviation starts in that area. Keeping God's word and not denying his name is said to be vital. When wrong teaching is tolerated in a fellowship, wrong behaviour will soon follow. When wrong behaviour is tolerated in a fellowship, wrong teaching will be close on its heels. Not keeping God's word leads to false teaching, while denying his name shows itself in sinful behaviour. Those two chapters in Revelation show that.