That which we have seen and heard declare we unto you, {2} that ye also may have fellowship with us: and truly our fellowship is with the Father, and with his Son Jesus Christ.

(2) The use of this doctrine is this, that all of us being coupled and joined together with Christ by faith, might become the sons of God: in which only consists all true happiness.

People's New Testament

1:3 That ye also may have fellowship. To declare what they had seen and heard was simply to preach the gospel. This knowledge communicated to others brought those who accepted it into a fellowship of knowledge and hope. Those are in fellowship who are partakers of the same faith, hopes, and privileges.

With us. All the saints entered into fellowship with the apostles, but the apostles were in

fellowship with the Father. This grand fellowship, that of the saints with the Father and the Son, is simply a guarantee that no good thing will be withheld from us; that all things are ours. There is a fellowship of peace, of concord, of eternal life and glory.

Wesley's Notes

1:3 That which we have seen and heard - Of him and from him. Declare we to you - For this end. That ye also may have fellowship with us - May enjoy the same fellowship which we enjoy. And truly our fellowship - Whereby he is in us and we in him. Is with the Father and with the son - Of the Holy Ghost he speaks afterwards.

Jamieson-Fausset-Brown Bible Commentary

3. That which we have seen and heard-resumed from 1Jo 1:1, wherein the sentence, being interrupted by 1Jo 1:2, parenthesis, was left incomplete.

declare we unto you-Oldest manuscripts add also; unto you also who have not seen or heard Him.

that ye also may have fellowship with us-that ye also who have not seen, may have the fellowship with us which we who have seen enjoy; what that fellowship consists in he proceeds to state, "Our fellowship is with the Father and with His Son." Faith realizes what we have not seen as spiritually visible; not till by faith we too have seen, do we know all the excellency of the true Solomon. He Himself is ours; He in us and we in Him. We are "partakers of the divine nature." We know God only by having fellowship with Him; He may thus be known, but not comprehended. The repetition of "with" before the "Son," distinguishes the persons, while the fellowship or communion with both Father and Son, implies their unity. It is not added "and with the Holy Ghost"; for it is by the Holy Ghost or Spirit of the Father and Son in us, that we are enabled to have fellowship with the Father and Son (compare 1Jo 3:24). Believers enjoy the fellowship OF, but not WITH, the Holy Ghost. "Through Christ God closes up the chasm that separated Him from the human race, and imparts Himself to them in the communion of the divine life" [Neander].

Matthew Henry's Concise Commentary

1:1-4 That essential Good, that uncreated Excellence, which had been from the beginning, from eternity, as equal with the Father, and which at length appeared in human nature for the salvation of sinners, was the great subject concerning which the apostle wrote to his brethren. The apostles had seen Him while they witnessed his wisdom and holiness, his miracles, and love and mercy, during some years, till they saw him crucified for sinners, and afterwards risen from the dead. They touched him, so as to have full proof of his resurrection. This Divine Person, the Word of life, the Word of God, appeared in human nature, that he might be the Author and Giver of eternal life to mankind, through the redemption of his blood, and the influence of his new-creating Spirit. The apostles declared what they had seen and heard, that believers might share their comforts and everlasting advantages. They had free access to God the Father. They had a happy experience of the truth in their souls, and showed its excellence in their lives. This communion of believers with the Father and the Son, is begun and kept up by the influences of the Holy Spirit. The benefits Christ bestows, are not like the scanty possessions of the world, causing jealousies in others; but the joy and happiness of communion with God is all-sufficient, so that any number may partake of it; and all who are warranted to say, that truly their fellowship is with the Father, will desire to lead others to partake of the same blessedness.