Unto the pure all things are pure. — The spirit of this famous saying of St. Paul, occurring almost in the same language in the Roman Letter (Romans 14:20), was the groundwork of much of the Gentile Apostle’s teaching. The words of the Lord Jesus above referred to (Matthew 15:2; Matthew 15:11) contain the same grand truth. “All things” include much besides mere food — in a word, include all acts connected with every-day life which in themselves are neither right nor wrong, neither good nor evil, but which derive their colouring of good or evil solely from the doer of the act. Bengel well sums this up in his “omnia externa eis, qui intus sunt mundi, munda sunt.”
But unto them that are defiled and unbelieving is nothing pure. — Here, as so often in these Pastoral Epistles, the last utterance, so to speak, of that grand life of St. Paul’s, purity and sound doctrine are inseparable. Here “the defiled,” “the polluted,” we are told, are the unbelieving; and to these, the Apostle says, nothing is pure. Yet there is nothing in God’s creation impure or evil — the evil and impurity are in the mind and heart of men; these may, and often do, defile and make impure the choicest gifts of God’s creation. One word is still left to be said on the teaching of this memorable verse. Who are the pure to whom all things are pure? Only those in this world who have sought cleansing by faith in the precious blood of Christ.
But even their mind and conscience is defiled. — Here St. Paul defines exactly the sphere over which the moral defilement of these hapless ones, who belong to the Christian company, alas, only in name, extends — the mind and conscience. The first of these — the mind — is the willing as well as the thinking part of man, as it has been well defined the human spirit (pneuma) in one of its aspects, not simply quatenus cogitat et intelligit, but also quatenus vult. Defilement of this mind (nous) means that the thoughts, wishes, purposes, activities, are all stained and debased. The second of these — the conscience (suneidçsis) — is the moral consciousness within, that which is ever bringing up the memory of the past, with its omissions and commissions, its errors, its cruel, heartless unkindness, its selfish disregard of others. When this is defiled, then this last safeguard of the soul is broken down. The man and woman of the defiled conscience is self-satisfied, hard, impenitent to the last.