16. They profess--that is, make a profession acknowledging God. He does not deny their theoretical knowledge of God, but that they practically know Him.
      deny him--the opposite of the previous "profess" or "confess" Him (1Ti 5:8; 2Ti 2:12; 3:5).
      abominable--themselves, though laying so much stress on the contracting of abomination from outward things (compare Le 11:10-13; Ro 2:22).
      disobedient--to God (Tit 3:3; Eph 2:2; 5:6).
      reprobate--rejected as worthless when tested (see on Ro 1:28; 1Co 9:27; 2Ti 3:8).

JFB.