Titus 1:15

Unto the pure all things are pure : but unto them that are defiled-is nothing pure; there is an allusion here to the stress laid by the false teachers on Jewish distinctions of clean and unclean meats, washing of hands, and other ceremonial purifications, while they took no pains to keep their hearts and lives clean from the defilement of sin. The apostle exposes their error by laying down a general principle applicable to all the relations of life. The pure are those whose hearts and lives are controlled by the holy principles of love, faith, and obedience towards God. To them all God's creatures are pure, and they need fear no defilement from them while they use them with thanksgiving in accordance with his word. Romans 14:14-20; 1 Timothy 4:4-5. All their daily labors, moreover, secular as well as religious, are pure, being all performed in the spirit of love towards God and man. The impure are those whose hearts and lives are under the control of selfish and base passions. To them nothing is pure; for their mind and conscience being defiled, every outward work that proceeds from them is unclean also. Those who love and practise what is good are constantly growing better, and those who love and practise evil are constantly growing worse.