I John 5:9

If, &c.--We do accept (and rightly so) the witness of veracious men, fallible though they be; much more ought we to accept the infallible witness of God (the Father). "The testimony of the Father is, as it were, the basis of the testimony of the Word and of the Holy Spirit; just as the testimony of the Spirit is, as it were, the basis of the testimony of the water and the blood" [BENGEL]. for--This principle applies in the present case, FOR, &c. which--in the oldest manuscripts, "because He hath given testimony concerning His Son." What that testimony is we find above in Jo1 5:1, Jo1 5:5, "Jesus is the Christ, the Son of God"; and below in Jo1 5:10-11.

In this chapter the apostle asserts, I. The dignity of believers (Jo1 5:1). II. Their obligation to love, and the trial of it (Jo1 5:1-3). III. Their victory (Jo1 5:4, Jo1 5:5). IV. The credibility and confirmation of their faith (Jo1 5:6-10). V. The advantage of their faith in eternal life (Jo1 5:11-13). VI. The audience of their prayers, unless for those who have sinned unto death (Jo1 5:14-17). VII. The preservation from sin and Satan (Jo1 5:18). VIII. Their happy distinction from the world (Jo1 5:19). IX. Their true knowledge of God (Jo1 5:20), upon which they must depart from idols (Jo1 5:21).