In Titus 1:15, Paul is saying that if the Judaizers are right in teaching that impurity makes everything it touches impure, then the fact that they are Cretans and all Cretans are liars, evil, and lazy, means that according to the theology of these Judaizers, even their mind and conscience are defiled.
Ephesians 4:17-19 is not teaching about Total Depravity or total inability, but about the devastating results of choosing sin over righteousness. Paul wants his readers to put off that old way of conduct, and live their new life in the Spirit with the new man which was created by God for righteousness and holiness (Ephesians 4:22-24).
Ephesians 2:1-3 is a favorite text for Calvinists to defend the idea of Total Depravity and total inability. This post shows what Ephesians 2:1-3 means. If Paul really means that those who are dead in sin cannot believe in Jesus, then the rest of his argument in the chapter and the letter become meaningless and senseless.
What does the word “dead” mean in the Bible? Does it mean non-existent or unable to act? No. A good synonym for “dead” is “separated.” This study looks at the seven types of death in the Bible and shows how in every case, to be dead is to be separated. Those who are dead can still be quite active in various ways.