Dear friend,
 
I'm afraid you haven't read Peter's entire epistle.  Of course the immediate context is about false teachers.  However, don't get caught in the hermeneutic trap of hyper-contextualization.  Peter claims at the beginning of the epistle, that Christians are saved "through the KNOWLEDGE of Him [Christ]" (2 Pet 1:3) and they have "ESCAPED the corruption that is in the world through lust" (1:4).  Then in chapter two, which you are addressing, Peter clearly speaks of the same type of person falling away and having a worse punishment than an unbeliever (2 Pet 2:20-22).  This person had previously "ESCAPED the pollutions of the world through the KNOWLEDGE of the Lord and Savior Jesus Christ" (2:20).  Both of these characteristics were the same ones listed at the beginning of the epistle concerning Christians (1:3-4).  How much clearer could it get?  In addition, KNOWLEDGE (Greek epiginosko - literally "exact knowledge") of Christ is always associated with saving knowledge (Rom 10:2, Eph 1:17, 4:13, Col 1:10, 2 Tim 3:7, Heb 10:26, 2 Pet 1:2-3, 1:8, 2:20).  2 Tim 3:7 specifically states that the wicked never come to the KNOWLEDGE of the truth.  Jesus says "This is life eternal, that they might KNOW thee..." (Jn 17:3).  So I'm sorry, but as adamant as you are on your theology, I believe my position is stronger Biblically.  Even so, I will not command you to repent nor condemn because that's just silly dogmatism. 
 
I would, however, ask you to be honest with yourself about about clear apostasy texts, such as Heb 10:26, 6:4-6, 3:12., John 15:2, Gal 1:6, etc.   I would also ask you to go and re-analyze your "eternal security" texts and you'll notice that many of them are stated in the following format:  "I am persuaded (confident) that........" (Rom 8:38, Heb 6:9, Php 1:6, 2 Th 3:4, 2 Tim 1:12).  A statement of confidence on Paul's part should never be considered an unconditional promise.  For even Joshua was given a promise of God's presence (seemingly unconditionally), yet we later see that the promise was clearly conditional (Compare Joshua 1:5,9 with Joshua 7:12).  These "confidence" statements of Paul don't have nearly the doctrinal weight as the texts offered for my position ("believer's security").  Thanks for your correspondence.