Conservative scholars are agreed that the Apostle John wrote five books of the New Testament: namely, the Gospel of John; the Epistles, I John, II John, and III John; and the Book of Revelation. It is usually supposed that the Gospel of John was written between 85 and 90 A.D. Also the Epistles were written about the same time. There are different views as to the date of the Book of Revelation. Many think that it was written around 95 or 96 A.D. It is not however, necessary for us to know the exact date. Some scholars are of the opinion that the Gospel of John was written first and that the First Epistle was written as a supplement to the Gospel. Others are of the profound conviction that I John was kind of a prologue—an introduction to the Gospel. Either view is possible. The same general teaching pervades both the Gospel and the First Epistle. In fact, the first four verses of the First Epistle could be considered as a summary of the prologue of the Gospel, John 1:1-18.

The Apostle John, the writer of the Books mentioned above, assumed the doctrine of the Holy Trinity, which is the basic teaching of the Scriptures. Moses declared the doctrine of the Trinity in Deuteronomy 6:4, which reads, when properly translated, "Hear O Israel, Jehovah our Gods is Jehovah a unity." Originally in the Hebrew language, nouns were singular, dual, or plural—the smallest plural being three. The word translated "our Gods" in this verse is a plural noun with the pronominal suffix our added. There is, therefore, echoed in this passage the doctrine of three personalities constituting the one, true, and living God. Those who do not recognize the doctrine of the Holy Trinity cannot possibly see aright scores and scores of passages of the Scriptures.

In First Samuel, chapter three, we have a record of God's calling Samuel into lifetime service. "Samuel grew, and Jehovah was with him, and did let none of his words fall to the ground. And all Israel from Dan even to Beer-sheba knew that Samuel was established to be a prophet of Jehovah" (I Sam. 3:19,20). In the next verse we are told: "And Jehovah appeared again in Shiloh; for Jehovah revealed himself to Samuel in Shiloh by the word of Jehovah." The adverb "again" in this quotation points back to the time that God appeared to Samuel in Shiloh when He gave him his original call to service, as we read in this chapter. The Lord's appearing to Samuel on this latter occasion is classified with the revelations that He had made to him in his early life. Concerning his call to service, we are told: "And Jehovah came, and stood, and called as at other times, Samuel, Samuel" (I Sam. 3:10). Jehovah Himself appeared to Samuel and gave him his call. Since this last statement (I Sam. 3:21), referring to the revealing of Himself to Samuel at a later date, speaks of Jehovah's revealing Himself by the Word of Jehovah, the former revelations were also the revelations of Jehovah by the Word of Jehovah. But, we are told that it was Jehovah Himself who appeared to Samuel and gave him his call. In one passage, the one appearing to Samuel is called Jehovah; in the other passage, the one appearing to Samuel is called the Word of Jehovah. When these facts are taken into consideration and read in the light of the New Testament, we are driven to the conclusion that Jehovah who at first appeared to Samuel in Shiloh is here called the Word of Jehovah. This statement in I Samuel 3:21 is, therefore, in anticipation of the doctrine of the revealing of the Second Person of the Trinity to man as seen in John 1:1-18—by the Word who became flesh and dwelt among us; namely, the Lord Jesus Christ.

In Isaiah, we have an impersonation of Messiah by the prophet who plays the role of King Messiah when He appears upon earth the first time. This impersonation is found in Isaiah 48:1-16. Upon an examination of these verses, it is clear that the prophet was impersonating God, the Messiah, the Creator of the universe. He concludes this prediction with the following statement:"Come ye near unto me, hear ye this; from the beginning I have not spoken in secret; From the time that it was, there am I: and now the Lord Jehovah hath sent me, and his Spirit"(Isaiah 48:16). Here, the Creator of the universe (Isa. 48:13) speaks of Jehovah, the Father, as having sent Him, Jehovah the Son, and also of His having sent Jehovah the Holy Spirit. Thus the three divine personalities constituting the one true and living God are clearly set forth in this verse.

In the world-wide commission, recorded in Mathew 28:19,20, the doctrine of the Holy Trinity appears in all its clarity. According to this passage Jesus said to His disciples, to whom He appeared on a certain occasion, that all authority in heaven and upon earth had been given unto Him—to Him the God-man, the glorified God-man. They were, therefore, to go and make disciples of all the nations "baptizing them in the name of the Father and of the Son and of the Holy Spirit: teaching them to observe all things whatsoever I commanded you: and lo, I am with you always, even unto the end of the world." The disciples are here commanded to baptize people into the name [a noun, in the singular number] of the Father and of the Son, and of the Holy Spirit. The three divine personalities appearing in this passage are co-eternal and co-equal.

In the passage under consideration, I John 1:1-4, two persons of the Holy Trinity appear-the Father and His Son, Jesus Christ. Though only two persons of the Holy Trinity are mentioned in these verses, the third person is mentioned in I John 3:24: "And hereby we know that he abideth in us, by the Spirit which he gave us."

A comparison of I John 1:1-4 with John 1:1-18 shows that the writer in both passages has the same person in mind, namely, the Eternal Son of God who laid aside the glory that He had with the Father from all eternity and entered the world by miraculous conception and virgin birth. In the Gospel record, John declares that "in the beginning was the Word and the Word was with God and the Word was God." In the First Epistle the same writer states, "That which was from the beginning, that which we have heard, that which we have seen with our eyes, that which we beheld, and our hands handled, concerning the Word of life. ..." The neuter relative pronoun translated "that which" and occurring four times in verse one is not used personally, but is employed by John to embrace the divine nature of the Son and His human nature. That which was from the beginning—the Eternal Son of God—combined with the human nature of the Lord Jesus Christ when He entered the world by virgin birth. In the Gospel of John the writer asserts that the Word was in the beginning with God and that life was in Him. Hence, He was and is the Word of Life. In this Epistle, John speaks of the Apostles' handling "that which" was from the beginning and of His being the Word of Life. In the Gospel, John declares that the Word was in the beginning, was God, and is God, and that this Word became flesh and dwelt among us (John 1:1,14). In view of these facts, it is quite evident that John in the Gospel is speaking in terms similar to those employed in the First Epistle and that he is speaking of the Lord Jesus Christ.

The Apostle in the Gospel asserts that the Word, the Eternal Word, became flesh and dwelt among us. It is clear by comparing this passage with others that John was talking about the incarnation, which was accomplished by miraculous conception and virgin birth. When the Eternal Word became flesh, He dwelt among men. For the first years of the earthly sojourn of Jesus, He lived a quiet life in Nazareth of Galilee. When He was about thirty, He stepped out on the stage of public activity and began His life's work in earnest. The initial step of His public activity was submitting to baptism by John, at which time the Holy Spirit descended in the form of a dove and rested upon Jesus. By this visible demonstration, Jesus was identified as the coming Messiah of Israel (John 1:29-34). After submitting to temptations by the Devil for forty days and winning a signal victory on every point, Jesus began to call His disciples. The first to receive the call were Andrew and Peter, his brother, and Philip and Nathanael. From time to time, Jesus called others of His disciples. He finally chose from His many disciples the twelve Apostles to be His representatives to the people.

For approximately three and a fraction years, Jesus gave special training to the Apostles, His ambassadors to the nations. The twelve Apostles were daily associated with Christ in a personal way in order that they might know thoroughly and understand His teaching and have the same attitude toward the world that He held. They walked with him, they talked with Him, they ate and drank with him, and were associated with Him under various and sundry conditions; and they, figuratively speaking, felt His pulse on all occasions. Thus, John could say, "That which was from the beginning, that which we have heard, that which we have seen with our eyes, and that which we have heard and our hands handled concerning the Word of Life. …" These statements applied to the relationship and association that the Apostles had with Christ during His earthly ministry. They, therefore, had the testimony of their various senses—of seeing, of touching, and of hearing, three of the five physical senses. To this statement we may add that they had a sixth sense by which they perceived Him. They felt in their very souls His holy and divine spiritual life and being. Everyone whom we meet has an effect upon our spirit, and we react to his personality. So the Apostles reacted to the spirit of Jesus as they did to no one else, because there is no one who is equal to Him. The Apostles, therefore, were absolutely certain with reference to the Lord Jesus and His being what they claimed He was.

But when He was crucified and slain, He was buried, and with Him were buried the hopes of the disciples (Luke 24:13-35). They had thought that He was the One who would redeem Israel; but, by His tragic death, He was cut off out of the land of the living. The Apostles, in despair, gave up all hope of His being the Messiah and Saviour of the world. But, when He was raised from the dead, they were begotten, as the Apostle Peter said, unto a living hope by the resurrection of the Lord Jesus (I Pet. 1:3-5).

After He was raised from the dead, He appeared at various times to the Apostles and to other disciples—on one occasion to above five hundred brethren at once. They were invited on one occasion to handle his body and see that He was not a spirit—that He was not a phantom, but a living person. The sixth sense, mentioned above, the contact of one spirit with another, confirmed to the Apostles that Jesus was the same One with whom they had been associated for three and a fraction years. They handled His body with their hands, they heard Him speak, and they examined Him critically and were convinced by the testimony of these various senses that He who appeared to them was none other than the One with whom they had been associated during His personal ministry, who had been crucified, but who had been raised from the dead, bringing life and immortality to life through the Gospel. In the bodily post-resurrection appearances to the disciples, there was present a new element, that of His glorified human nature added to His natural being. Thus the association with the glorified Jesus was a new hope and a richer experience than that which Apostles had enjoyed with Him prior to His glorification. The apostle had fellowship with the glorified Christ.

John, therefore, wrote his letter to all disciples, showing them the joys and the spiritual riches of the fellowship that they may enjoy with Christ. He wanted the believers to have the same spiritual experiences daily. For this purpose, the Apostle wrote this Epistle.