“Unto the pure all things are pure, but vnto them that are defiled, and vnbeleeuing, is nothing pure: but euen their mind and conscience is defiled.”
1611 King James Version (KJV)
1:15 To the pure - Those whose hearts are purified by faith this we allow. All things are pure - All kinds of meat; the Mosaic distinction between clean and unclean meats being now taken away. But to the defiled and unbelieving nothing is pure - The apostle joins defiled and unbelieving, to intimate that nothing can be clean without a true faith: for both the understanding and conscience, those leading powers of the soul, are polluted; consequently, so is the man and all he does.
Tit 1:15 Unto the pure all things are pure. In the "Jewish fables" just referred to (Tit 1:14) were rigid regulations concerning foods and purifications. Hence Paul adds, "It is not food that makes one impure. To the pure all things are pure. When one is unbelieving and defiled, no food can make him pure". See notes on Ro 14:14 1Co 8:4-8.