Titus 1:10 says, For there are many unruly and vain talkers and deceivers, specially they of the circumcision: Paul said many men were unruly, vain talkers, and deceivers. He said this was especially true of the circumcised, or the Jewish people. They as whole still denied that Jesus Christ was the Messiah, and they still do today.
Verse eleven adds, Whose mouths must be stopped, who subvert whole houses, teaching things which they ought not, for filthy lucre's sake. Paul said such men should have their mouths stopped since they could subvert whole families. I don't believe he meant they should be killed, but only that they should not be listened to. He also said that many of them did this for the sake of filthy lucre, or money and riches. There are many people who declare things that they say come from God but point to riches in the world instead of faith in God.
Verse twelve continues, One of themselves, even a prophet of their own, said, the Cretians are alway liars, evil beasts, slow bellies. Paul said even one of their own who was a prophet said the Cretians were always liars. It seems to me that he was talking about a Jewish prophet, since he said the prophet was one of their own. There are some people today who profess to be Christians who teach things that go against God's word, and we should never listen to them.
Verse thirteen states, This witness is true. Wherefore rebuke them sharply, that they may be sound in the faith; Paul said this witness from the Jews was true and that they should sharply rebuke those who taught any way to salvation other than through faith in Jesus Christ. We still need to sharply rebuke those who teach anything other than God's word, especially when it comes to salvation, which is possible only by putting our faith in Jesus Christ.
Verse fourteen adds, Not giving heed to Jewish fables, and commandments of men, that turn from the truth. Paul told Titus that he was not to take heed of the fables of the Jews and the commandments of men which led people away from the truth. The Jewish people always had more laws and commandments than God's word gave, and these did and still do led people away from the truth of God. So do many things that some non-Jews who profess to be teaching God's word.
Verse fifteen continues, Unto the pure all things are pure: but unto them that are defiled and unbelieving is nothing pure; but even their mind and conscience is defiled. Paul said to the pure, those redeemed by the sacrifice of Jesus Christ on the cross, that all things were made pure. He also said that for those who weren't that nothing was pure. If we believe that salvation comes only from faith in Jesus Christ, He makes us pure before God, and if we don't, nothing we believe or do will make us pure before God.
Verse sixteen concludes, They profess that they know God; but in works they deny him, being abominable, and disobedient, and unto every good work reprobate. Paul said such men professed to know God but that their works denied this and they were abominable, disobedient, and in all good work reprobate. This will always be true.