Does 2 Peter 2:1 Deny Effectual Atonement@taisto
2 Peter 2:1, ". . . But there were false prophets also among the people, even as there shall be false teachers among you, who privily shall bring in damnable heresies, even denying the Lord that bought them, and bring upon themselves swift destruction. . . ."
Primary cross reference.
Jude 1:4, ". . . For there are certain men crept in unawares, who were before of old ordained to this condemnation, ungodly men, turning the grace of our God into lasciviousness, and denying the only Lord God, and our Lord Jesus Christ. . . ."
As John Owen points out in The Death of Death in the Death of Christ, the word used to say the false teachers were "bought" can be used to denote any kind of deliverance, and so does not necessarily indicate that they had been purchased by the blood of Christ. Based on the context, it may be best to understand the statement that the false teachers had been "bought" not as a reference to the death of Christ, but a reference to some other act of deliverance--such as deliverance by God's goodness from the idolatry of the world. Notice how later on Peter refers to the false teachers as having had a form of "deliverance" in that they "escape[ed] the pollution of the world" by the knowledge of the gospel (v. 20). This verse is not referring to salvation, but outward reformation with no ultimate inward reality.