We saw in yesterday’s study that Jeremiah 9:23-24 speaks of some characteristics of God that are to be found in His people.
In the same way, Jeremiah 31:34 speaks of the knowledge of God that God’s people will possess in the latter days: “And they shall teach no more every man his neighbor, and every man his brother, saying, Know the LORD; for they shall all know me, from the least of them unto the greatest of them, saith the LORD.” But this verse is preceded by a statement of how this will become possible: “I will put my law in their inward parts, and write it in their hearts, and will be their God, and they shall be my people.” Moreover, it is followed by the ethical statement, “I will forgive their iniquity, and I will remember their sin no more.”
There is no knowledge of God without an accompanying righteousness, for God is righteous. This is John’s point. It is the first test by which we may know that we know Him. John is not insensitive to the concerns of his contemporaries. Did the Greeks want to come into touch with reality? So does John. Did the most sensitive people of his day want to know God? This is also John’s aspiration. But the questions are: How do you know Him? And how do you know that you know Him? John’s answer is that you know Him when you come into contact with a personality that changes your personality and specifically leads you to live a righteous life.
Why is the righteous life a proof that we know God? Because it is not natural to sinful man. Consequently, it is proof of a divine and supernatural working in our lives if we obey Him. Paul makes the same point when he follows his admonition to the Philippians to “work out” their salvation with the profound observation, “For it is God who worketh in you both to will and to do of his good pleasure” (Phil. 2:13).
At this point John introduces two types of men, as if to make the test concrete. On the one hand, there is the man who claims to know God but who does not keep His commandments. John calls him a liar. On the other hand, there is the man who obeys God out of a genuine love of Him. John does not even say that this man claims to know God; but he does know Him, as his conduct indicates.
John has very harsh words for the person who claims to know God but who does not obey God’s commandments. He calls him a liar. That is, he is neither deceived by someone else nor confused. Rather, he is openly professing something which he knows is not true and therefore should rightly be branded a deceiver. Moreover, says John, “the truth is not in him.” This phrase may be no more than a restatement of the claim that the man professing to know God while actually disobeying His commandments is a liar, but it may also mean more than this. It may mean that the truth is not to be found in him in the sense that the one seeking truth should go, not to this man, but rather to another source. If this is the case, then the phrase quite obviously applies to the false teachers of John’s day, whom true seekers after God should avoid, and to teachers in our time also. It means that the truth should be sought, not from the man who has intellectual qualifications alone, but rather from the man whose claim to know spiritual things is backed up by godlike conduct. Unless there is observable godliness, such a man’s teachings about God should be distrusted.