The revelation of God the Father in the Person of God the Son is the heart of the gospel message. The gospel can only be “good news” to one who knows this truth. In a very real way, then, eternal life is knowledge – not simply an acquisition of information, but rather a personal, intimate knowledge of the one true God revealed in the Lord Jesus Christ (John 17:3). But in addition to knowledge, eternal life also involves an act of personal belief: “As many as received Him, to them He gave the right to become children of God, even to those who believe in His name” (John 1:12). Knowledge and belief, thus, form a unity as they relate to eternal salvation.
Salvation results from belief (John 3:16), but belief itself is dependent upon knowledge in two critical ways. First, belief is necessarily preceded by knowledge. One cannot believe in something or someone about which he is deceived or knows nothing at all. One must have knowledge of that which he is asked or commanded to believe in. This is the purpose of John’s gospel and the central theme of the Upper Room Discourse: “These have been written so that you may believe that Jesus is the Christ, the Son of God; and that believing you may have life in His name” (John 20:31). Second, belief is not only preceded by knowledge, it is also confirmed by knowledge. One can only know that he has truly believed if he has knowledge of those evidences which reveal the character of true belief. For this reason, John provided his readers with a follow-up tract: “These things I have written to you who believe in the name of the Son of God, so that you may know that you have eternal life” (1 Jn. 5:13). The Upper Room Discourse, therefore, is related to John’s first epistle just as belief is related to knowledge: whereas salvation is believing because one has come to know, assurance of salvation is knowing that one has truly come to believe.
Jesus spent the last night before His crucifixion alone with His disciples, manifesting Himself to them through a dialogue known as the Upper Room Discourse (John 13-17). John introduces the discourse by disclosing to the readers the very reality that Jesus wished to disclose to His disciples, namely “that the Father had given all things into His hands, and that He had come forth from God and was going back to God” (13:2). After three chapters of dialogue, the disciples finally come to understand: “Now we know that You know all things, and have no need for anyone to question you; by this we believe that You came from God” (16:30). At this, Christ had fully accomplished His discipling ministry and could acknowledge with satisfaction before the Father that His disciples had “truly understood that I came forth from You, and they believed that You sent Me” (17:4, 8).
Jesus manifested Himself to His disciples through a rich and masterfully-orchestrated conversation which He personally initiated by means of a characteristic demonstration of servanthood. Christ’s supreme example of humility in washing the disciples’ feet is all the more stunning when contrasted with the dark and satanic transgression simultaneously committed by Judas the betrayer (13:1-30). But while Judas was guilty of the most infamous act of treason the world could ever know, he was not the only disciple who would fail the Lord that night. After learning that he must allow Christ to serve him or he in turn would never be able to serve Christ, the impetuous Peter also discovered, despite his boasting to the contrary, that his promises of loyalty would prove worthless and empty (13:31-38). Despite suffering temporary desertion by His disciples, Jesus promised that He would never leave them as orphans (14:1-15). Instead, He would provide them with a Helper, the Spirit of truth, Who would guide and comfort them as they faced rejection and persecution from the world (14:16-31; 15:18 – 16:15).
At the very heart of Jesus’ eleventh-hour discourse is His command that His disciples abide in Him and love one another (15:1-17). It is, in fact, through the vehicle of sacrificial love that Jesus most powerfully communicated the knowledge of the Father. Abiding in Him would result in fruitfulness, thus glorifying the Father. And, as a slave is never greater than his master, the disciples should serve and love one another in the same way that He has served and loved them (13:12-17; 15:12). By abiding in Him and loving one another, the world would know that they are truly His disciples (13:35; 15:8). Because obedience is basic to love, no less than four times Jesus explicitly tells His disciples that if they truly loved Him, they would obey Him (14:15, 24; 15:10, 14). Jesus, however, was not telling His disciples something that He Himself was unwilling to do. Indeed, His perfect obedience to the Father was the very example that they were to follow (14:31; 15:10; 17:4).
One could not imagine a greater demonstration of love and obedience than the Son of God humbly laying down His own life for His friends (15:13). In rather cryptic language, Jesus foretells of His coming death and resurrection, saying “a little while, and you will no longer see Me; and again a little while, and you will see Me.” With His disciples understandably perplexed by the figurative speak, Jesus further explains that “you will weep and lament, but the world will rejoice; you will grieve, but your grief will be turned into joy” (16:20). Finally, Jesus promises His disciples that if they ask the Father for anything in His name that they could be assured that the Father would grant their request (16:23-27).
At last departing from the use of figurative language, Jesus completed His self-disclosure with a plain statement of truth: “I came forth from the Father and have come into the world; I am leaving the world again and going to the Father” (16:28). At this point the disciples were fully persuaded that Jesus had truly manifested the Father to them. Specifically, the disciples had: (1) come to know that all that the Son had given them had come from the Father; (2) received the words which the Father had given the Son to give to them; (3) understood that the Son came forth from the Father; and (4) believed that the Father had sent the Son (17:7-8). What Jesus knew of Himself (13:1-4), He manifested to them (13:5 – 16:28). And by this the disciples believed unto salvation and the work of Christ was accomplished (16:30; 17:3-8).
In his first epistle, the Apostle John picks up right where the Upper Room Discourse ends. The Word of Life had already been disclosed unto men, “and we have seen and testify and proclaim to you the eternal life, which was with the Father and was manifested to us” (1:2). Having been fully persuaded by the Son concerning the Father, John now proclaims with unqualified conviction that “our fellowship is with the Father, and with His Son Jesus Christ” (1:3). And whereas the gospel of John was written so that one might believe unto eternal life, the first epistle of John was written that one might have full confidence that he has in fact exercised sincere faith in the divine truth. Accordingly, First John is a letter of confirmation to those who have already believed, providing a series of examinations by which his readers can know for certain that they have come to faith in the Son of the living God. But these examinations, which are indicated by the repetition of the phrase “by this we know,” or an equivalent, are not intended to illicit morbid introspection. Rather, they are intended to provide assurance of salvation so that the believer may have joy to the fullest extent possible in his fellowship with God and his brothers (1:4). The evidences of true faith fall into six general categories:
Evidences that we know God (2:3-14). According to John, we can know that we truly know God if we keep His commandments and walk in the same manner that He walked (2:3-14). On the contrary, the one who claims to know God yet resists His Word is a liar. And what is His commandment? That we love one another (John 15:12) In what manner did He walk? As a humble servant washing the feet of His disciples (John 13:1-17).
Evidences to discern the saved and the unsaved (2:15 – 3:10) . Having personally witnessed a wolf among sheep in Judas, John is especially concerned that his readers be equipped to discern the children of God from the children of the devil. A child of the devil loves the world; a child of God should not (2:15-17). A child of the devil might graze among the sheep for a time, but in the end he will be exposed as an imposter (2:18-24). All who practice righteousness are children of God; all who practice sin are children of the devil (3:4-10).
Evidences of the love of God (3:11-23) . The supreme evidence of the love of God, the act which alone is sufficient to demonstrate His infinite love, is the Son of God’s sacrifice of His own life for the brethren (3:16). The love of God is further manifest, however, in that it moves us to love the brethren in like manner (3:11-22). And just as Christ’s demonstration of and teaching on love forms the very core of the Upper Room Discourse, the commandment of God to believe in Jesus and love one another stands at the very heart of John’s epistle (3:23).
Evidences of the ministry of the Spirit (3:24 – 4:14) . Jesus promised that “in that day” His disciples would know the fellowship of the Father and the Son (John 14:20), a knowledge that would be imparted through the ministry of the Holy Spirit (14:16-31; 16:5-15). But because of the infiltration of deceiving spirits, John is compelled to explain how his readers might discern the true Spirit. First and foremost, “every spirit that confesses that Jesus Christ has come in the flesh is from God; and every spirit that does not confess Jesus is not from God” (4:2-3a). Further, the Spirit of truth is in agreement with, yeah, has animated the teaching of the apostles (4:6).
Evidences that we love the brethren (4:15 – 5:4) . God is love (4:16). Therefore, if one says that he abides in God, he ought to demonstrate that by loving God’s children. But not only do we know that we love God by the fact that we love His children, but also “we know that we love the children of God, when we love God and observe His commandments” (5:2). According to John, it is not only an act of love toward God to love the brethren; additionally, it is also an act of love toward the brethren when we love God.
Evidences of answered prayer (5:5-17). Because Jesus overcame the world (John 16:33), we too are overcomers through our faith in Him (5:4). Such faith leads to boldness in prayer: “This is the confidence which we have before Him, that, if we ask anything according to His will, He hears us” (5:14). It should be duly noted, however, that we must “ask according to His will.” Jesus put it this way: “If you abide in Me, and My words abide in you, ask whatever you wish, and it will be done for you” (John 15:7). When we are in obedience to Him, we can expect Him to fulfill any request that we have of Him, a sure evidence that we belong to Him.
The Upper Room Discourse comes to an end with Jesus successfully manifesting Himself to His disciples such that they know who He is, where He came from, and where He is going. As a result, they believed in Him unto eternal life (John 17:3). Similarly, First John comes to a close with the disciples’ confession that they have received the Father and the Son: “And we know that the Son of God has come, and has given us understanding so that we may know Him who is true” (5:20a). That is the same conviction that the disciples expressed in the gospel of John (16:30). But John’s epistle takes the believer one step further. Whereas his gospel revealed the truth of Christ by which we are brought to faith, the epistle reveals the knowledge that confirms that “we are in Him who is true, in His Son Jesus Christ” (5:20b). And as Christ revealed and John explains, to know the Son is to know the true God; to know the true God is to have eternal life; and to know that you know is to walk in the fulness of joy.