Here the apostle advises the Corinthians, instead of inquiring after the proof of Christ in him, to examine whether they were in Christ themselves; intimating to us, that such are usually most backward to examine the state of their own souls, who are forward to enquire into the spiritual state and condition of others. "You seek a proof of Christ in me, says the apostle: Oh, rather prove and examine yourselves."
Where note, 1. A duty expressed; Examine yourselves; prove yourselves: The word is a metaphor taken from goldsmiths, who with great exactness try their gold; the truth of it by the touchstone, the weight of it by the scale, and the purity of it by the fire. And the repetition of the command, Examine yourselves; prove yourselves; implies the great backwardness that is in men's natures to perform this duty, the great necessity of the duty, and the great diligence and frequency to be used in performing of the duty.
Learn hence, That self-examination is an excellent, a necessary and important duty, belonging to every one in the church, and requires great diligence and faithfulness in the performing of it. 'Tis necessary, in regard of our comforts, and also in regard of our graces; for there are counterfeit graces, as well as real; and common graces, as well as saving; and 'tis a duty that requires diligence and frequency, because the work is difficult, because the heart is backward, because we are apt to be deceived, and willing to be deceived; because many have miscarried without is, and many perish by a negligent performance of it: Therefore examine yourselves; prove yourselves.
Note, 2. The subject-matter of our examination, whether ye be in the faith; that is, whether ye be converted to the Christian faith, whether the faith of Christ be in you, whether the pinciple of faith be in your consciences, whether the practice of faith be in your lives, whether your faith be the parent and principle of obedience, working love, and working by love.
Note, 3. The enforcement or motive to this duty, Except ye be reprobates; that is, counterfeit, adulterate, unsound, and insincere Christians, unaccepted of God, and not owned by him. As reprobate silver has no worth or fitness in it for trading, so such Christians as, upon examination are not found to have the grace of faith in them, more precious than gold, are unapproved of God, and rejected by him.
Note, 4. When the apostle expostulates with them, and says, Know ye not your ownselves? it implies both the folly and unreasonableness of the neglect of the duty, and also the possibility and easiness of knowing whether Christ be in us, or not, upon a due and diligent inquiry, whether we have experienced the quickening and transforming power of Christ in our hearts and lives.
Finally, So great is the benefit, and so sweet the comfort, which flows to us by examinations and self-acquaintance, that it will abundantly recompence our care and diligence, in the frequent and faithful discharge of it.