Despite their confident promises, heretics are in a dreadful position. The blackest darkness has been reserved for them (2 Peter 2:17). They are worse off than they were at the beginning (2 Peter 2:20). It would have been better for them not to know the way of righteousness (2 Peter 2:21).
Having joined the church, false teachers continue to indulge their sinful desires by showing themselves to be slaves of depravity. For some of them this will be revealed in adultery and other sexual sins, for others it will be revealed in gluttony and the pursuit of riches. Either way, their life is not focused on turning from sin and growing in godliness, but doing that which makes them happy. They live for themselves and they encourage others to do the same.
In this the heretics are different from Christian believers. Those who belong to Christ also struggle with sin, but we do not persevere in unbelief. We do not justify our sins, pretending as if selfishness is good or calling sin a blessing. This is what the heretics do, which is why they are in a worse position than when they did not know anything of Christ. They use the gospel to justify their lust and sin. They abuse God’s grace, claiming that there is no need to repent. Their hearts have been hardened and they are not open to hearing the gospel.
In turning from Christ to sin, these false teachers show that they never truly belonged to Jesus. Their actions reveal their true nature. They are unbelievers who are in the covenant community without being united to Christ through faith.
17 These are waterless springs and mists driven by a storm. For them the gloom of utter darkness has been reserved.