“Profane” (v.16) means unholy (Ezek.22:26), and “holy” means set apart to God (Ex.20:8). If the Jews didn’t keep the sabbath holy, God considered it profane (Ezek.22:8). So what kind of profane babblings was Paul telling Timothy to shun?
Well, since verse 16 begins with a “but,” and the previous verse speaks of rightly dividing the Word, the profane words he has in mind are words that aren’t rightly divided. We saw in Verse 14 he has the words of the law in mind. The words of the law were holy for the Jews, but unholy when placed on us since we’re not under the law. For instance, we don’t have to keep the sabbath (Col.2:16), so putting Exodus 20:8 on us is unholy.
Some parts of the law are interdispensational, of course. It is always wrong to take God’s name in vain (Ex.20:7) because His name is holy (Lu.1:49). When the Jews didn’t treat it as holy, God considered it profane (Ezek.36:20). “In vain” means for no reason, no purpose, so when Paul says to shun “profane and vain babblings” (2:16) it is because the law serves no purpose for us.
When he says the words of the law will increase unto “more ungodliness,” that must mean the words of the law are ungodly in and of themselves. Religion always is! (IITim.3:5). When the Galatians messed with the Law they were “removed” from God (Gal.1:6). That’s ungodly!
Paul says these profane babblings will “increase” because sin always increases! Carnal sin spreads like leaven (ICor.5:6) and so does legalism (Gal.5:9). The only way to keep it from spreading is by rightly dividing the word and paying heed to Paul’s gospel (ITim.6:19,20).
Speaking of things that spread, Paul says that unrightly divided words will eat like a canker (2:17). The Greek word is gaggraino, from which we get gangrene. Gangrene is dead flesh that eats up living flesh and spreads, like the words of Hymenaus and Philetus. Hymenaeus was sailing along with Paul, teaching what he taught, when he “made shipwreck” of the faith (ITim.1:19,20) when he stopped teaching what Paul taught. Here we learn he did so by teaching the resurrection was past (2:18).
Paul called that erring from the faith because he is thinking of how the Lord said that to deny the resurrection was an error (Mark 12:18-27). Some of the Corinthians were denying the resurrection (ICor.15:12) and it was overthrowing their faith (v.13-19). But misplacing the resurrection will overthrow faith just as much! And the word “overthrow” means the complete destruction of something (cf.Ex.14:27; Jer.49:18).
The resurrection for us is the one associated with the Rapture (ICor.15:51-53), and if you thought it was past and you were still here, you’d think you’re not saved! Paul’s answer to this is to insist the Lord knows them that are His (2:19). He has always known His own (Nahum 1:7,8; John 10:4), and always seals His own (John 10:27,28). And now He knows you (Gal.4:9), and has sealed you (Eph.1:13). The fact that He knows us is our seal (2:19).
Old Testament seals identified a document with the king (Esther 8:8), and our baptism into Christ identifies us with Him (Rom.6:3-5). That means not even God can reverse your seal (cf.Esther 8:8; Daniel 6:17). Job could be confident of his salvation (Job 19:25-27) because God sealed his sins (Job14:17). Jeremiah bought some land and the seal was evidence of his purchase (Jer.32:10,11), and the Spirit is the evidence that your body is His purchased possession (Eph.1:13,14). You’re sealed with the same Spirit the Lord was (John 1:33,34; 6:27). We know God never loses any that He seals because He will seal 144,000 on earth (Rev.7:3,4) and all make it to heaven before God’s throne (Rev.14:1-5). Not even the devil can break our seal (cf.Rev.20:1-3).
Religion says you can’t tell men they are sealed and can’t be lost, they’ll live in sin, but Paul says we should “depart from iniquity” (cf.Eph.4:30).