Titus 1:15

The pure. That is, the pure in heart (see on Matt. 5:8), those who understand righteousness by faith and who are aware of the dangers of the Jewish system of ritual and ceremony and Jewish fables (Titus 1:14).

All things. See on 1 Cor. 6:12. Paul here deals with Jewish ritual purity. He distinguishes between those who attempt to compensate for a lack of moral purity by ceremonial purifications, and those who believe that ceremonial performances are not essential to the development of a God-approved life. Paul does not here imply that the Christian is free to engage in practices condemned elsewhere in Scripture, or that Biblical prohibitions regarding moral conduct or dietary practices do not apply to Christians. Compare Christ’s teaching in Mark 7:19 (see comment there and on Rom. 14:20).

Them that are defiled. That is, those who have not been converted and who do not know the peace that accompanies righteousness by faith. They are the “unbelieving,” who refuse to comply with Paul’s gospel, the “gainsayers” (v. 9).

Their mind. That is, their way of thinking, their attitude. Compare Rom. 7:23; Eph. 4:23; Phil. 4:7; 2 Tim. 3:8. The “defiled and unbelieving” allow their minds to be governed by unsanctified desires. For a discussion of the effect of conversion upon the mind see on Rom. 12:2; cf. on Phil. 4:8.

Conscience. The consciousness of moral right and wrong is dulled when the mind elects to dwell on unsanctified desires. Under such circumstances the conscience cannot function effectively. Like a magnetized compass it ceases to be an accurate and reliable guide.