The third of John’s tests is expressed in these verses as belief. Indeed, it is with this concept that the section both begins and ends (vv. 1, 5); between belief that “Jesus is the Christ” and belief that “Jesus is the Son of God” is found John’s discussion of both love and obedience. The implication is that, just as it is impossible to have love without obedience or obedience without love, so also is it impossible to have either love or obedience without belief in Jesus as the Christ and the Son of God. It was to lead men and women to this twofold confession that John’s Gospel was written (John 20:30-31).
John has talked about the content of the Christian’s faith several times before. The new element in these verses is that of victory, expressed as an overcoming of the world. This is found three times: once, in the first half of verse 4, in the statement that whatever is born of God overcomes the world; again, in the second half of verse 4, in the statement that the active ingredient in this victory is faith; and, finally, in verse 5, in the rhetorical question: “Who is he that overcometh the world, but he that believeth that Jesus is the Son of God?”
These three statements express three important principles. First, that which is victorious over the world is that which has its origins in God. Indeed, if it were not for the reality of that new life which springs from God and which is implanted within the Christian, no victory would be possible. There is the world without. John has spoken of this in chapter 2:15-17, referring to the lure of all that is in the world as “the lust of the flesh, and the lust of the eyes, and the pride of life.” There is also the world within. He has discussed this in terms of those false teachers who pretended to be among God’s people but who were actually of the world, which they revealed by leaving the Christian assembly (2:19). How can any Christian resist such diverse and insidious evils? He could not, were it not for the fact of the new birth and for the truth that He that is within the Christian is greater than he that is within the world.
The second principle involved in the Christian’s victory is faith, which John defines as faith in Jesus as the Christ and as the Son of God. The importance of this confession is seen in contrast to the denial of these truths by the Gnostics, but the confession is equally important for our age. No one would deny that other points of doctrine are important. But since Jesus is the center of Christianity, obviously the truth about Him is most important and, in fact, determines what is to be believed in other areas.
The third principle of victory is faithfulness. This is always involved in the idea of “faith” as the Bible defines it. It is not just a past overcoming that John is thinking of (one of the occurrences of this word is in the aorist tense), but also a present overcoming (the other two occurrences are in the present tense) through a continuing and persevering faith in Jesus Christ. This is the same sense in which the word is used in Christ’s messages to the seven churches of Asia Minor in Revelation, where the phrase “to him that overcometh” occurs seven times. There, as in John, it is not a superior class of Christians that is involved, nor those who do some great work as the world might evaluate it. It is rather those who remain faithful to the truth concerning Jesus as the Christ and who continue to serve Him.
This the Christians to whom John is writing have done through their faithfulness in view of the Gnostic threat, and this all who truly know the Lord will do also. Indeed, in the broadest view the faithfulness is not theirs, but rather His who has brought them to spiritual life and who, as a result, has also led them to faith in Christ, a pursuit of righteousness, and love for other Christians.