These words make up the first four verses of the Bible book we know as 1 John. Yes, John has written before and we should be able to tell from his style of writing, this text carries some of the same writing characteristics as the gospel of John. Its the type of writing that gets the reader involved in coming to understand, which, in turn brings the reader into an even deeper understanding.
Much of the first four verses of the book could have been replaced with the simple statement, "I am going to write to you about Jesus." But John wanted his readers to know so much more about our Lord. That's why the opening of this discourse emphasizes it's content is about one which was "from the beginning." Here we are near the end of the written word of God and John uses an introduction which takes us all the way back prior to Genesis to let us know he is writing about one who has been around since the beginning.
Not only that, John said, "We have heard him, we have seen him with our eyes, we have even touched him, and here is what we proclaim ......he is the Word of life!" John continues, "The life appeared, " and notice John's words and some additions to his introduction, "we have seen it and testify to it, and make the proclamation that this one who was with the Father has also appeared to us."
Here then, is the reason John uses this way to introduce his book of the Bible. by a somewhat extravagant introduction of Jesus. "We proclaim to you what we have seen and heard, so that you also may have fellowship with us. And our fellowship is with the Father and with his Son, Jesus Christ."
John then says, "We write this to make our joy complete." The complete joy, according to John, comes with the sharing of the "Word of life." John's writings touch on subjects like fellowship, loving one another, forgiving, and relationships. The beauty of this section of scripture comes into focus when we realize our walk with the "Word of life" takes us into that fellowship and love, and forgiving, and most important, a relationship with God and his eternal family.