Titus 1:12-16 (ESV)
“One of the Cretans, a prophet of their own, said, "Cretans are always liars, evil beasts, lazy gluttons."  This testimony is true. Therefore rebuke them sharply, that they may be sound in the faith,  not devoting themselves to Jewish myths and the commands of people who turn away from the truth.  To the pure, all things are pure, but to the defiled and unbelieving, nothing is pure; but both their minds and their consciences are defiled.  They profess to know God, but they deny him by their works. They are detestable, disobedient, unfit for any good work. “
“That they may be sound in the faith, not devoting themselves to Jewish Myths, and the commands of people who turn away from the truth.” The extent today with which Jewish Myths are synonymous with Christianity is shameful. Jewsih Myths have always been that which has plagued the Christian Church. They were rampant in the days of Christ, and caused many not to recognize their messiah. The myths concerning the Jewish Messiah, looked forward to an earthly messiah who would rule Israel as David did, and subdue once again their earthly enemies, and vindicate those who lived a “righteous life”. This myth has been resurrected in the Christian church many times. It relegates the gospel and salvation to an earthly realm. Then it makes salvation the reward for living according to the law. You see this today in all the millennial hype. This isn’t the only form of false doctrine, but it is one that has been quite destructive for a long time. Perhaps no one is literally arguing for circumcision, but the premise is the same.
They profess to know God, but deny him by their works. It is funny. Today people think they confess Christ with their works. It is precisely this that Paul is getting at. It isn’t that these people were leading immoral lives, and there by denying God. They were denying God, but putting their faith in their works, rather than in Christ’s work. If one sets about to do good works in order thereby to gain salvation, they deny God with their works. Christ is not confessed by living a morally upright life. Christ is confessed in words, for it is with your hearts that you believe and are justified, and with your mouths that you confess and are saved. Good works are good, but they are no place for faith.