The Apostle passes continually from one aspect of this truth to another. He exhorts them now to confidence in Christ; now warns them against discouragement and despair, and now against false confidence and carnal security. His admonitions always keep in view both directions in which they are liable to go astray. Accordingly he here comes back again, to warn them against the false confidence of a merely seeming christianity, and to fix attention upon the characteristic marks of the true. |And hereby we do know that we know him, if we keep his commandments.|

In contrast with a professed |knowing of Christ| which is contradicted by the life, John represents this as the sign of a true knowledge of Christ, viz. that we obey his commandments. There is indeed a knowledge which belongs only to the understanding, and has nothing to do with the life; but such, in reference to divine things, could not be admitted by John as real; he did not even allow it the name of knowledge. For as truth according to his modes of thought is not a mere abstraction, belonging solely to the understanding, but is something pertaining to the inner life, to the affections; so to him knowledge, in reference to divine things, is not merely a matter of speculation and of the understanding, but is something proceeding from the inner life, and as such must manifest itself in the outward course of conduct. The sum and substance of the knowledge must be actually present in the inner life. It presupposes an inward fellowship of life with that which is known; and this must stamp its own peculiar character upon the whole life. The knowledge of Christ, as the Holy One, can only exist where there is spiritual fellowship with him, the Holy One; where the soul has received into itself his holy image, and has been pervaded by its influence. And where this is the case, it must show itself in the whole conduct by the test here pointed out, obedience to the commands of Christ; for the commands of Christ are inseparable from his own nature, from himself. As in all which proceeds from him he but presents himself; so his commands are but single features of the new life proceeding from him. Thus each one, by subjecting his life to a comparison with the commands of Christ, may ascertain whether the knowledge of Christ, to which he makes claim, be truth or appearance merely. True indeed, John could not admit, as we have before shown, that the life of any believer could present an absolutely perfect fulfilment of the commands of Christ. He cannot, therefore, so understand this test of christian self-knowledge; otherwise the result must in every case be unfavorable. But with all the imperfections which still encumber the christian life, there yet remains a strongly marked distinction between those with whom obedience to Christ's commands is a matter of earnest purpose, the current of whose whole life sets in this direction; and those to whom the desire to obey him is in no sense the soul of their life. Moreover, as different degrees obtain in the true and living knowledge of Christ, there will be likewise corresponding grades of obedience to the commands of Christ. The touchstone of all true religious knowledge, according to this view of John, is the practice of it in the life. But as his manner is, he here merely contrasts opposites in respect to their essential nature, without taking into account any gradations in the outward manifestation. How entirely opposed is the standard of judgment here established by John, to a one-sided speculative orthodoxy, a conception of truth as something merely theoretical, an orthodoxy of the understanding, not of the life! Orthodoxy, in the sense of John, is something which belongs to the life. How different an aspect would it have given to doctrinal controversies, had this stand-point of the Apostle been rightly understood and firmly adhered to!

Ch, ii.4

In order to impress the truth more strongly by exhibiting it on both sides, John now, in his own peculiar manner, expresses in a negative form what he had first presented affirmatively. |He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.|

In John's view, therefore, there is an inherent inconsistency in professing to know Christ, and yet not obeying his commands. One who does this he regards as a liar; and declares, as the ground of the disposition from which such conduct proceeds, that the truth is not in him. We must here apply what we have previously remarked respecting John's conception of truth. Plainly he here speaks of truth as something which has to do with the disposition, the moral feelings. Such an one is represented by John as, in the determining tendency of his spirit, in his affections, estranged from the truth; as one in whom falsehood is the inwardly ruling principle. He is wanting in honest self-examination in relation to divine truth; hence, he does not consider what is requisite in order to make such a profession in truth, what is involved in the claim of knowing Christ. Thus arises first, self-deception, unconscious hypocrisy; and from this proceeds the conscious falsehood of seeking to appear more than lie really is.