2 Peter 2:1:

Denying] By total apostasy, or evil life, unbelieving the servants of Christ, Tit. 1:16. See more on Jude 4.

The Lord that bought them] That gave a price sufficient for them, even his own precious Blood, Acts, 20:27; 1 Cor. 6:20; 1 Pet. 1:18, 19. Or, by whom they professed that they were redeemed: and therefore they should not have denied him.

Annotations Upon all the Books of the Old and New Testament: This Second Edition so enlarged, As they make an entire Commentary on the Sacred Scripture: The like never before published in English. Wherein The Text is Explained, Doubts Resolved, Scriptures Paralleled (London: Printed by John Legat, 1651). [No pagination.]

Jude 4:

ungodly men] Such as worship God not aright; or have no fear of God at all, Gen. 20:11; Psa. 30:1; Rom. 3;18.

turning the grace of our God into lasciviousness] The grace of God invites us to sobriety, Tit. 2:11,12, but they turn it to a contrary end.

Denying the only Lord God, and our Lord Jesus Christ] Denying Christ to be God, who was their master by profession (for the professed themselves to be of his household) and their Lord by public authority over them. Or, by their deeds denying Christ.

Annotations Upon all the Books of the Old and New Testament: This Second Edition so enlarged, As they make an entire Commentary on the Sacred Scripture: The like never before published in English. Wherein  The Text is Explained, Doubts Resolved, Scriptures Paralleled (London: Printed by John Legat, 1651). [No pagination.]

[Notes: These two brief comments demonstrate that the early Reformed theology was able to interpret these verses in such a way that Christ, as Lord and Master, is the subject, while also allowing that the “buying” was by way of a sufficient redemptive price for them.]