I’m sure you’ve heard of absent-minded professors, men who are so engrossed in their deep thoughts that they tend to lose track of the little things we must all keep in mind in order to get along in life. Well, in Paul’s letter to Titus, the apostle warned the young man about some false teachers, saying,
“…even their mind… is defiled. They profess that they know God; but in works they deny Him, being abominable, and disobedient, and unto every good work reprobate” (Titus 1:15,16).
From the context, we know that these defiled-minded professors were the “vain talkers… of the circumcision” (Tit. 1:10) who were “teaching things which they ought not” (v. 11). I think Paul called them “defiled” because these unsaved Jews were trying to teach the grace believers in Crete’s churches that they would be defiled if they ate meats prohibited by the law of Moses, for that’s what the law said of such people (Lev. 11:43).
But it doesn’t say that about those of us who are not under the law, but under grace (Rom. 6:15 cf. I Tim. 4:1-5). Paul just finished saying of us, “unto the pure all things are pure” (v. 15), speaking of the foods we eat (cf. Rom. 14:20). So Paul turned the tables on those defiled-minded professors, and said that it was “their mind” that was actually “defiled” for thinking that way, not the people who ate those meats!
When Paul said that these defiled-minded professors were “abominable,” he is again turning the tables on those legalizers. You see, “abominable” is another word the law used of those who ate unclean meats (Lev. 11:41-43). So in calling the legalizers “abominable,” Paul is assuring the grace believers in Crete’s churches that they weren’t abominable, their accusers were.
Finally, Paul calls these legalizers “reprobate” (Tit. 1:16). That’s a word that the dictionary defines as abandoned, and that’s how the word is used in Scripture as well. In speaking of the Gentiles who lived before Abraham, God said that He had to give them up and give them over to “a reprobate mind” (Rom. 1:24,26,28). That’s pretty much the definition of abandonment, and that’s why Paul called those ancient Gentiles reprobate.
But the unsaved Jews in Paul’s day had become just as reprobate! When Paul says that they were reprobate “unto every good work,” that meant they were totally incapable of doing anything that pleased God. No wonder the apostle Paul, in speaking of both Jews and Gentiles, wrote:
“God hath concluded them all in unbelief, that He might have mercy upon all” (Romans 11:32).
Today, unsaved Jews are just as defiled-minded as unsaved Gentiles, but God is willing to have mercy on them all. All He asks is that they believe the only reason they’re worthy of Heaven is that Christ paid for their sins on the cross of Calvary and rose again. If you’re not saved, “Believe on the Lord Jesus Christ, and thou shalt be saved” (Acts 16:31). source