But false prophets also arose among the people, just as there will also be false teachers among you, who will secretly introduce destructive heresies, even denying the Master who bought them, bringing swift destruction upon themselves.
That’s the cultic angle of Calvinism.
Calvinist, Collin Maxwell, explains: “If He did, then here is solid evidence that He died for those other than His own elect because these men (being damnable heretics) are in hell. How do Calvinists answer this objection to our doctrine of Particular Redemption i.e. that all for whom Christ died will eventually be saved and be in Heaven? Read on! ... In keeping with the general tenor of Scripture that God cannot know frustration in those things which He sets out to do (Isaiah 46:10 etc.,) we believe that their purchase was professed and not actual i.e. they denied the Lord whom they professed to have bought them.” (Did Christ Purchase with His own Blood the Apostates in 2 Peter 2:1?, emphasis mine)
However, Maxwell cites 1st John 1:10 in his unique view: “If we say that we have not sinned, we make Him a liar and His word is not in us.” In other words, God says that we are sinners. So if we contradict Him, we are, in effect, calling God a liar. Obviously God is not a liar. This is just a way of speaking. So the question is whether or not Peter is using a similar expression concerning 2nd Peter 2:1.
Maxwell comments: “Do they actually make Him to be a liar...or do they (by their denial of His charges against them) profess Him to be a liar? Obviously the latter. No one can make anybody (never mind God) an actual liar - the only one who can actually make you a liar is yourself (i.e. when you tell lies) But anyone can profess you to be a liar - just spread the rumour and the deed is done. It was on this principle that Potiphar’s wife got Joseph sent to prison for adultery - it was professed rather than actual.” (Did Christ Purchase with His own Blood the Apostates in 2 Peter 2:1?, emphasis mine)
Calvinist, William MacDonald, explains: “Here we should pause to remind ourselves that while these false teachers to whom Peter refers had been bought by the Lord, they had never been redeemed. The NT distinguishes between purchase and redemption. All are purchased but not all are redeemed. Redemption applies only to those who receive Jesus Christ as Lord and Savior, availing themselves of the value of His shed blood (1 Pet. 18, 19).” (Believer’s Bible Commentary, p.2295, emphasis mine)
MacDonald is a 4-Point Calvinist who teaches an Unlimited Atonement. In contrast, 5-Point Calvinists have typically taught that Jesus did not purchase everyone, but only those of the eternal flock of the Father, such that the false teachers of 2nd Peter 2:1 falsely claimed that Jesus bought them. Still, others, have taught a universal purchase, though with a Particular Redemption of just the elect [in the Father]. The reasoning uses an analogy of buying a candy bar. You don’t buy the candy bar in order to get the wrapper. The wrapper just happens to come along with the candy. When you buy it, you eat the candy and throw the wrapper in the trash. Therefore, God bought all men with the intention of getting “the elect,” whereas the unwanted, unloved and spiritually aborted non-elect are then discarded into the dumpster of an eternal Hell. A similar analogy involves the purchase of a piece of land:
MacDonald explains: “In Matthew 13:44 the Lord Jesus is pictured as a man who sold all He had to buy a field. In verse 38 of that same chapter, the field is distinctly said to be the world. So by His death on the cross, the Lord bought the world and all who are in it. But He did not redeem the whole world. While His work was sufficient for the redemption of all mankind, it is only effective for those who repent, believe, and accept Him.” (Believer’s Bible Commentary, p.2295)
Whereas MacDonald’s conclusion is biblically accurate, the interpretation of the parable of Matthew 13:44, may be incorrect. Consider the interpretation of J.C. Ryle:
Calvinist, J.C. Ryle, provides an alternate interpretation of the parable of Matthew 13:44: “The parables of the ‘treasures hidden in a field’ (verse 44) and the ‘merchant looking for fine pearls’ (verses 45-46) appear intended to convey the same lesson. They vary, no doubt, in one striking way: the ‘treasures’ was found by someone who does not seem to have sought it; the ‘pearl’ was found by one who was actually looking for pearls. But the conduct of the finders, in both cases, was precisely alike: both ‘sold all they had’ to make the thing they had found their own property; and it is exactly at this point that the instruction of both parables agrees. … These two parables are meant to teach us that those who are really convinced of the importance of salvation will give up everything to win Christ and eternal life. What was the conduct of the two men our Lord describes? One was persuaded that there was a ‘treasure hidden in a field,’ which would amply repay him if he bought the field, however great the price. The other was persuaded that the ‘pearl’ he had found was so immensely valuable that he wanted to buy it at any cost. Both were convinced that they had found a thing of great value: both were satisfied that it was worth a great sacrifice now to make this thing their own. Others might wonder at them; others might think them foolish for paying such a sum of money for the ‘field’ and ‘pearl,’ but they knew what they were about. They were sure that they were getting a bargain. We see, in this simple picture, the conduct of a true Christian explained. He is what he is, and does what he does in his religion, because he is thoroughly persuaded that it is worthwhile. He comes out from the world; he puts off the old man; he leaves the vain companions of his past life. Like Matthew, he gives up everything, and like Paul, he considers ‘everything a loss’ (Philippians 3:8) for Christ’s sake. And why? Because he is convinced that Christ will make amends to him for all he gives up. He sees in Christ an endless ‘treasure,’ he sees in Christ a precious ‘pearl’: to win Christ he will make any sacrifice. This is true faith. This is the stamp of a genuine work of the Holy Spirit. (Matthew: Ryle, The Crossway Classic Commentaries, pp.109-110)
Ryle’s interpretation is consistent with the message of Christ as recorded in the Gospel of Matthew: “If anyone wishes to come after Me, he must deny himself, and take up his cross and follow Me.” (Matthew 16:24)
Nevertheless, the Arminian view is that God purchased everyone with the intention of redeeming anyone
who might believe in His Son. Calvinists do not believe that anyone could, in light of the total depravity of man, and therefore Arminians point Calvinists to the supernatural (John 6:63), faith-giving (Romans 10:17), power (Romans 1:16) of the living and active Gospel (Hebrews 4:12) which is able to save souls (James 1:21), and presents that as the solution to man’s inability, in conjunction with the intervention of Christ’s draw (John 12:32) and the Holy Spirit’s universal conviction. (John 16:8)
Calvinists raise several arguments concerning the impact of a universal purchase, which you may also refer to here.