2 Tim. 2:16-19 (ESV)
But avoid irreverent babble, for it will lead people into more and more ungodliness,  and their talk will spread like gangrene. Among them are Hymenaeus and Philetus,  who have swerved from the truth, saying that the resurrection has already happened. They are upsetting the faith of some.  But God's firm foundation stands, bearing this seal: "The Lord knows those who are his," and, "Let everyone who names the name of the Lord depart from iniquity."
Swerved from the truth, saying that the resurrection has already happened. False doctrine, this is the irreverent babble that needs to be avoided and which leads people into more and more ungodlieness. I imagine this was some sort of pre-millennialism, which the Christian church inherited from the synagogue, the Jewish myths that Paul warns Titus of. I never knew this until recently, but many evangelicals think a doctrine is only false if it deals with directly with Christ’s resurrection. However, false doctrine that leads to unbelief has many heads. It is important that we pay close attention to all of God’s word. Here we see pre-millennialism claiming the souls of some. What we teach regarding Baptism, and the Lord’s Supper is no less important. A little leaven leavens the whole lump. We need to be on guard, and avoid false doctrine in all its forms. It may not lead to unbelief in all, but do we want to be responsible for leading anyone astray? I sure don’t.