Verse 20. And we know that the Son of God is come. We know this by the evidence that John had referred to in this epistle, 1 Jo 1:1-4; 1 Jo 5:6-8.

And hath given us an understanding. Not an "understanding" considered as a faculty of the mind, for religion gives us no new faculties; but he has so instructed us that we do understand the great truths referred to. See Barnes "Lu 24:45".

All the correct knowledge which we have of God and his government, is to be traced directly or indirectly to the great Prophet whom God has sent into the world, Joh 1:4,18; 8:12; Joh 9:5; Heb 1:1-3; Mt 11:27.

That we may know him that is true. That is, the true God. See Barnes "Joh 17:3".

And we are in him that is true. That is, we are united to him; we belong to him; we are his friends. This idea is often expressed in the Scriptures by being "in him." It denotes a most intimate union, as if we were one with him or were a part of him -- as the branch is in the vine, Joh 15:4,6. The Greek construction is the same as that applied to "the wicked one," 1 Jo 5:19, (en tw alhyinw.)

This is the true God.* There has been much difference of opinion in regard to this important passage; whether it refers to the Lord Jesus Christ, the immediate antecedent, or to a more remote antecedent -- referring to God, as such. The question is of importance in its bearing on the doctrine of the divinity of the Saviour; for if it refers to him, it furnishes an unequivocal declaration that he is Divine. The question is, whether John meant that it should be referred to him? Without going into an extended examination of the passage, the following considerations seem to me to make it morally certain that by the phrase "this is the true God," etc., he did refer to the Lord Jesus Christ.

(1.) The grammatical construction favours it. Christ is the immediate antecedent of the pronoun this -- outov. This would be regarded as the obvious and certain construction so far as the grammar is concerned, unless there were something in the thing affirmed which led us to seek some more remote and less obvious antecedent. No doubt would have been ever entertained on this point, if it had not been for the reluctance to admit that the Lord Jesus is the true God. If the assertion had been that "this is the true Messiah;" or that "this is the Son of God;" or that "this is he who was born of the Virgin Mary," there would have been no difficulty in the construction. I admit that this argument is not absolutely decisive; for cases do occur where a pronoun refers, not to the immediate antecedent, but to one more remote; but cases of that kind depend on the ground of necessity, and can be applied only when it would be a clear violation of the sense of the author to refer it to the immediate antecedent.

(2.) This construction seems to be demanded by the adjunct which John has assigned to the phrase "the true God" -- " ETERNAL LIFE." This is an expression which John would he likely to apply to the Lord Jesus, considered as life, and the source of life, and not to God as such. "How familiar is this language with John, as applied to Christ! 'In him (i.e. Christ) was Life, and the LIFE was the light of men -- giving LIFE to the world -- the bread of LIFE. -- my words are spirit and LIFE -- I am the way, and the truth, and the LIFE. This LIFE (Christ) was manifested, and we have seen it, and do testify to you, and declare the ETERNAL LIFE which was with the Father, and was manifested to us,' 1 Jo 1:2." -- Prof. Stuart's Letters to Dr. Channing, p.83. There is no instance in the writings of John, in which the appellation LIFE, and eternal Life, is bestowed upon the Father, to designate him as the author of spiritual and eternal life; and as this occurs so frequently in John's writings as applied to Christ, the laws of exegesis require that both the phrase "the true God," and "eternal life," should be applied to him.

(3.) If it refers to God as such, or to the word "true" -- ton alhyinon [yeon] -- it would be mere tautology, or a mere truism. The rendering would then be, "That we may know the true God, and we are in the true God: this is the true God, and eternal life." Can we believe that an inspired man would affirm gravely, and with so much solemnity, and as if it were a truth of so much magnitude, that the true God is the true God?

(4.) This interpretation accords with what we are sure John would affirm respecting the Lord Jesus Christ. Can there be any doubt that he who said, "In the beginning was the Word, and the Word was with God, and the Word was God;" that he who said "all things were made by him, and without him was not anything made that was made;" that he who recorded the declaration of the Saviour, "I and my Father are one," and the declaration of Thomas, "my Lord and my God," would apply to him the appellation the true God!

(5.) If John did not mean to affirm this, he has made use of an expression which was liable to be misunderstood, and which, as facts have shown, would be misconstrued by the great portion of those who might read what he had written; and, moreover, an expression that would lead to the very sin against which he endeavours to guard in the next verse -- the sin of substituting a creature in the place of God, and rendering to another the honour due to him. The language which he uses is just such as, according to its natural interpretation, would lead men to worship one as the true God who is not the true God, unless the Lord Jesus be Divine. For these reasons, it seems to me that the fair interpretation of this passage demands that it should be understood as referring to the Lord Jesus Christ. If so, it is a direct assertion of his divinity, for there could be no higher proof of it than to affirm that he is the true God.

And eternal life. Having "life in himself," (Joh 5:26,) and the source and fountain of life to the soul. No more frequent appellation, perhaps, is given to the Saviour by John, than that he is life, and the source of life. Comp. Joh 1:4; 5:26,40; 10:10; 6:33,35,48,51,53,63; Joh 11:25; 14:6; 20:31; 1 Jo 1:1,2; 5:12.

* Many MSS. here insert the word God -- "the true God" -- ton alhyinon yeon, this is also found in the Vulgate, Coptic, AEthiopic, and Arabic versions, and in the Complutensian edition of the New Testament. The reading, however, is not so well sustained as to be adopted by Griesbach, Tittman, or Hahn. That it may be a genuine reading is indeed possible, but the evidence is against it. Lucke supposes that it is genuine, and endeavours to account for the manner in which it was omitted in the MSS. -- Commentary, p.349.

{a} "understanding" Lu 24:45 {b} "This" Isa 9:6