Verses 1–4 of chapter one constitutes the prologue to the letter. Its unusual structure can be confusing. Notice after verse 1 there is a dash in the ESV translation, followed by another dash at the end of verse 2. Verse 2 is a parenthetical statement. Verse 3 reverts back to the thought at the end of verse 1: “that which we have seen and heard.” This is followed by the main verb in the paragraph: “we proclaim also to you.” This is the most important semantic information John is conveying in verses 1–3. Maybe it will be easier to understand what John is saying if you read it like this: “We proclaim to you that which was from the beginning, that which we have heard, that which we have seen, that which we have looked at, that which we have touched with our hands, concerning the Word of Life.”
In verse 3 John writes, “that which we have seen and heard, we proclaim also to you.” Here John returns to his thought from verse 1. John has been proclaiming Jesus through his preaching and now does so through his writing. John is simply saying this: “The Jesus I saw and heard many years ago is the Jesus I have been proclaiming and continue to proclaim.” John was both an eyewitness and an ear–witness. Verse 3 provides the reason why John is proclaiming Jesus to his readers and to us: “so that you too may have fellowship with us.”
In 1 John 1:1-3, John has affirmed the reality of Christ eternally, historically and experientially.
The paragraph, 1:1-4, essentially is constructed in two major sections. These would essentially serve as the main points of the text. Semantically, vv. 1-2 function as something of a description followed by two declarations, the first in v. 3 and the second in v. 4.
John Declares Jesus as the Word of Life – (1–2).
John Declares his Purpose in Writing: Fellowship and Joy – (3–4).