(and the life was revealed, and we have seen, and testify, and declare to you the life, the eternal life, which was with the Father, and was revealed to us);
And then the third reason why he wrote the epistle is in chapter 5, verse 1Jo 1:13 . "These things have I written unto you that believe in the name of the Son of God, that you may know that you have eternal life." Written to believers for the purpose of bringing them assurance of their salvation, "That you may know that you have eternal life." So, to bring you fullness of joy, freedom from sin, and assurance of eternal life, those are the purposes for which John wrote this epistle.