A  ¹That which was from the beginning,

B  which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, concerning the Word of life—

A  ² the life was manifested,

B’  and we have seen, and bear witness, and declare to you

A  that eternal life which was with the Father and was manifested to us—

B’  ³ that which we have seen and heard we declare to you,

C  that you also may have fellowship with us;

C’ and truly our fellowship is with the Father and with His Son Jesus Christ.

C’  ⁴ And these things we write to you that your joy may be full.

A: Jesus Christ: Eternally-Existing, Manifesting Himself on Earth, and by Nature is Eternal Life.
B:  We have heard, seen, beheld, touched, bear witness, and declare.
C: The 3-Fold Purpose.