2 Corinthians 13:5 Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates?
Paul begins this final chapter of his second letter to the church at Corinth by telling them, once again, that sin within the body of Christ will not be tolerated. If established and proven by two or three witnesses, offenders will be sufficiently warned to repent of their sinful ways - he will not spare, or overlook, their offenses, but will condemn them severely. He also defends his apostleship, which had been denied by false prophets among them. He assures them that when he once again meets with them face to face, that he will prove his calling, by demonstrating the might of God, through his Savior, Jesus Christ, who lives in him.
Until he is able to come to them, for the third time, he tells them to examine yourselves, whether ye be in the faith. Due to the influence that had been exerted by false prophets, within the church at Corinth, Paul asks all of them to examine themselves in order to test their faithfulness. They were not to examine others, but, rather, to examine their own faith, to determine if they were truly children of God, in Christ, and if they were abiding by the inspired testimony of Christ, which he had delivered to them. The examination of one's faith was not a new concept that came into existence when the New Covenant was ushered in. David wrote in Psalm 139:23-24, Search me, O God, and know my heart: try me, and know my thoughts: and see if there be any wicked way in me, and lead me in the way everlasting. Jeremiah, the probable author of the book of Lamentations, wrote, Let us search and try our ways, and turn again to the Lord (Lam. 3:40).
Self-examination of one's faith is not to be done once and then forgotten; it must be a constant, daily, on-going examination. Unfaithfulness does not replace faith in God, through Christ, overnight; it does so gradually; it does so over time. By continually examining your faith, you will be able to recognize and prevent, at its inception, sin that is constantly trying to creep into your life and lead you into unfaithfulness. The very foundation on which Christians stand, is their faith that God's promise of eternal salvation has been filled through His Son, Jesus Christ. This faith must hold firm at all times; it must never waver; it must never be jeopardized by the sinful influence of Satan through his false teachers. This can only be is avoided by the constant examination of one's faith, and comparing it to that which God requires of His children.
Further, Paul tells the church at Corinth, prove your own selves. We prove our faith to God by doing His will. But we also must prove our faith to ourselves. We do this, as we often must, every time we go into the world, and remain unaffected by its sinful ways. Our faith in the sustaining power of God, is tested with each trial and temptation we face in life. We prove our faith in God by demonstrating the love for our fellowman at every opportunity we have to help those having physical or spiritual need. These, as well as many other ways, we are able to prove our faith to God as well as to ourselves. By knowing what God requires of us, we have the measure by which we are able to prove our actions. God's approval will only be given to those that know His will and obediently carry it out to the letter.
Paul asks this question: Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates? Rhetorically, Paul is telling the Corinthian brethren that they CAN know that Jesus Christ is in them, and are constantly being led by God through Him. That is, with one exception - except ye be reprobates. They can know their faith is leading them in the way God wills them to go, unless their faith has been corrupted by the wisdom of mankind - specifically faith in the doctrine of the false prophets, which were misleading members of the church of Christ in Corinth. False Christianity can only be recognized, made known, and avoided when one is well founded in the knowledge of God's word.
To know that Jesus Christ is in you, and contrary-wise, to know that you are in Jesus Christ, is assured when you know, by comparing your conduct of life with God's will - that you are walking in the same pathway of life as required by your Savior, Jesus Christ. God's commandments, as revealed through His Son, and by His Holy Spirit-inspired disciples of Christ, is our guide. He that keepeth His commandments dwelleth in Him, and he in Him (1 John 3:24a). Therefore, examine yourselves. Blessed are those that know God's will, are in Christ, and are not found wanting!