At the conclusion of his Gospel, when John writes that Jesus promised him that he would never taste death, he identified himself as “that disciple whom Jesus loved.”
20 Then Peter, turning about, seeth the disciple whom Jesus loved following; which also leaned on his breast at supper, and said, Lord, which is he that betrayeth thee?
21 Peter seeing him saith to Jesus, Lord, and what shall this man do?
22 Jesus saith unto him, If I will that he tarry till I come, what is that to thee? follow thou me.
23 Then went this saying abroad among the brethren, that that should not die: yet Jesus said not unto him, He shall not die; but, If I will that he tarry till I come, what is that to thee?
24 This is the disciple which testifieth of these things, and wrote these things: and we know that his testimony is true.
25 And there are also many other things which Jesus did, the which, if they should be written every one, I suppose that even the world itself could not contain the books that should be written. Amen. (John 21:20-25)
John, still in character, is not telling us more of his personal details than he feels we need to know, so we have to go to Jesus’s explanation to his Nephite disciples to learn more about John’s mission.
6 And he said unto them: Behold, I know your thoughts, and ye have desired the thing which John, my beloved, who was with me in my ministry, before that I was lifted up by the Jews, desired of me.
7 Therefore, more blessed are ye, for ye shall never taste of death; but ye shall live to behold all the doings of the Father unto the children of men, even until all things shall be fulfilled according to the will of the Father, when I shall come in my glory with the powers of heaven.
8 And ye shall never endure the pains of death; but when I shall come in my glory ye shall be changed in the twinkling of an eye from mortality to immortality; and then shall ye be blessed in the kingdom of my Father.
9 And again, ye shall not have pain while ye shall dwell in the flesh, neither sorrow save it be for the sins of the world; and all this will I do because of the thing which ye have desired of me, for ye have desired that ye might bring the souls of men unto me, while the world shall stand.
10 And for this cause ye shall have fulness of joy; and ye shall sit down in the kingdom of my Father; yea, your joy shall be full, even as the Father hath given me fulness of joy; and ye shall be even as I am, and I am even as the Father; and the Father and I are one (3 Nephi 28:6-10).
Even though that concludes John’s Gospel, it does not end his testimony. He bore that testimony in his epistles. Some of the most beautiful and profound literature in the New Testament is the First Epistle of John where we read:
1 That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life;
2 (For the life was manifested, and we have seen it, and bear witness, and shew unto you that eternal life, which was with the Father, and was manifested unto us;)
3 That which we have seen and heard declare we unto you, that ye also may have fellowship with us: and truly our fellowship is with the Father, and with his Son Jesus Christ.
4 And these things write we unto you, that your joy may be full.
5 This then is the message which we have heard of him, and declare unto you, that God is light, and in him is no darkness at all.
6 If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth:
7 But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin (1 John 1:1-7).
15 Whosoever shall confess that Jesus is the Son of God, God dwelleth in him, and he in God.
16 And we have known and believed the love that God hath to us. God is love; and he that dwelleth in love dwelleth in God, and God in him.
17 Herein is our love made perfect, that we may have boldness in the day of judgment: because as he is, so are we in this world.
18 There is no fear in love; but perfect love casteth out fear: because fear hath torment. He that feareth is not made perfect in love.
19 We love him, because he first loved us.
20 If a man say, I love God, and hateth his brother, he is a liar: for he that loveth not his brother whom he hath seen, how can he love God whom he hath not seen?
21 And this commandment have we from him, That he who loveth God love his brother also (1 John 4:15-21)