faith that doesn't actually save anyone must indeed be categorized as a strange and wasted religiosity. If Peter presented "like precious faith" in 2nd Peter 1 (and he did), then here in 2nd Peter 2 he presents the false apostate philosophies of the many religions; religions that are deviations from the gospel truth. He labels the proponents of renegade gospels as "false prophets" and "false teachers" (vs. 1). These are heretics in the realest sense. They are the proponents of heterodoxies that detract from the exclusivity of Christ; espousers of false doctrines that damn every soul that follows their hellish lies. Peter classifies all of these vain faiths as apostate religions, implying that in every case there was truth in their past that was willingly forsaken (Romans 1). Each religion that teaches anything other than salvation by grace through faith in Jesus Christ is a strange faith. Faith in a powerless object is blatant foolishness. So, Peter pulls no punches as he decries the evils of any religious teaching that contradicts the gospel of Christ.
While the death of Christ was certainly aimed at every soul (vs. 1 & 1st John 2:2), the leaders of spiritual coups d’état are categorized as hopelessly lost (Psalm 2:1-9, Jude 1:4-19, 1st John 2:18-19, Hebrews 6:4-8, 10:25-31, 12:8, 15-17 & Revelation 17). Specifically, those who once held the full gospel of Jesus Christ during the dispensation of grace (who were formerly professors of faith in Christ and were appendages of the church - 1st Timothy 3:15 & Matthew 16:18) are in more trouble than Peter can find ways to describe (vs. 4-9).