John provides the reader of his gospel with six major themes which, when understood within their context, have multifarious applications for the modern reader and to the body of Christ at large. The six major themes of the Gospel of John are God, the Christ, salvation, the Spirit, the new covenant community, and last things. Each has subsumed within it thematic elements which transcend John’s Gospel and which, perhaps more importantly, can be related to the holistic message revealed throughout Scripture.
Kostenberger avers that God as outlined in John is chiefly characterized by two overarching concepts: “the one who sent Jesus and as the Father of the Son” . These conceptualizations of God are important to understand as the focus of John’s Gospel is relayed through the modality by which John presents God. The focus of John’s Gospel is not on God Himself, but instead on His Son. The Jewish people were cognizant of and had a devout belief in a monotheistic God. This is evidenced by the Shema, the chief prayer of Judaism and an “affirmation of Judaism and a declaration of faith in one God” . The purpose of John’s writing was not to develop additional theology concerning God. His purpose was to reveal, initially to the Diaspora Jews and Jewish proselytes and eventually to the world, that Jesus was the Messiah; a belief which unfortunately has largely not taken root among many Jews. Modern believers can take heart that Jesus took the form of man, experienced all the issues that humanity has to deal with on a daily basis and yet was still without sin. He was the perfect sacrifice for our sins and thus has provided us with a modality by which we can have a relationship with God the Father. This is a message which the church today needs to explicate more than ever not only to the members of the congregation but to the world at large.
Contextually, the main thrust of John’s Gospel is essentially a systematic theological lesson in Christology. As noted by D.A. Carson, “John’s presentation of who Jesus is lies at the heart of all that is distinctive in this Gospel” . The purpose and function of Christ is clearly revealed in the Johannine text serving to explicate not only His divinity but also his humanity. John, throughout his text, utilizes numerous titles for Christ in an effort to reveal the aforementioned attributes of Christ. Perhaps the most lucid demonstration of Christ’s divinity in John is the comparison of Christ to the “Word.” As noted by Kostenberger, this “establishes a connection between God’s act of creation through his Word and his act of providing salvation through the incarnate Word, Jesus” . It is this connection between creation and redemption that is essentially the scarlet thread running throughout not only John’s Gospel but all of Scripture. Perhaps we often forget who Jesus is as outlined by John. Jesus is not a New Testament phenomenon or some well meaning sage who did some good on this earth. Believers must grasp hold of the concept that Jesus is God and is eternal. He was involved in the creation of the universe and chose to suffer on our behalf. Additionally, there is a holistic element to Scripture that is revealed in John. Jesus is the “I AM.” It can be stated that subsumed within the pages of John’s Gospel is the heart of the redemptive message of Scripture. God loves his creation and He has provided a means by which humanity can escape eternal damnation. It is obvious this is a message which the body of Christ needs to rediscover.
Yet another important theme in the Gospel of John is that of salvation. John clearly denotes that salvation is of the Jews indicating the “framework for Jesus’ understanding of his own mission is shaped by the Scriptures mediated by the Jews” . Additionally, it must be stated that John’s work is inherently rooted in the genre of gospel with the sole purpose of all activities depicted within his text concurrently pointing toward the “cross and the resurrection” . So as not to indicate that salvation is for Jews only, John clearly outlines in the famous verse John 3:16 that the promise of salvation from sin and the eternal death subsumed therein is available to everyone who believes. Perhaps this is why the Gospel of John is one of the most popular books of the New Testament for new believers and, in conjunction with Romans, a powerful tool by which believers can share the gospel message and plan of salvation.
Interestingly, among all of the Gospels, it is the Gospel of John which contains the most numerous teachings on the topic of the Holy Spirit. Kostenberger notes that the term parakletos or helping presence is “only used in this Gospel to designate the Holy Spirit” . The overarching teaching of John in his Gospel concerning the Holy Spirit is to explicate the mission of the Holy Spirit; that of the provider of explaining the teachings of Scripture and indwelling the believer following Christ’s ascension. Modern believers often view the Holy Spirit solely as a post-Acts discussion point when it is clearly evident that the mission and purpose of the Holy Spirit is a vital element of John’s message. Much can be gleaned from the pages of John’s gospel concerning the working of the Holy Spirit in the daily life of the believer.
While the nomenclature of church or ekklesia is absent from the Gospel of John, the concept of church and the future function of this organization is lucidly apparent. Perhaps the teaching of the church within John’s Gospel can best be depicted as an outline of what it means to be the New Testament Community rather than a brick and mortar church. There is no indication of the somewhat popular “replacement theology” that has been popularized by many in the dispensational theological camp. What is discussed is a “gradual building from physical following to a spiritual following of Jesus that is not constrained by limits of time and space” . The church is depicted as an outgrowth of Christ as the vine with his followers, the church, being the branches. Carson rightly avers that the “elements of what it means to belong to the people of God, what it means, in fact, to be the church, are richly present” . While the technicalities and procedures of the church as an organizational entity are absent from John’s Gospel, there is abundant discussion of what it means to be the people of God living in unity focused on a common purpose.
The concept of eschatology is replete throughout the Gospel of John. It can be stated that “according to John, we can have eternal life now and already have passed from death over into life” . While the Synoptic Gospels spent considerable time discussing the Kingdom of God, John instead focuses on the concept of eternal life. The similarities between the two concepts are abundant. There is a notably Old Testament sense to John’s eschatology reflecting the traditional Jewish understanding of redemption as revealed in this age and finally in the age that is to come . The collective of New Testament corpora depict that the believer can experience redemption in the present with a constant attitude of looking to the final redemption that will be revealed at the Parousia. The Gospel of John emphasizes the “present enjoyment of eschatological blessings”  while pointing the reader to the ultimate enjoyment of the redeemed creation.
 Andreas Kostenberger, Encountering the Gospel of John (Grand Rapids: Baker Academic), 39.
 Jewish Virtual Library, “The Shema”; available from http://www.jewishvirtuallibrary.org/jsource/Judaism/shema.html; Internet; accessed 18 May 2009.
 D.A. Carson, The Gospel According to John (Grand Rapids: Wm. Eerdmans Publishing Company), 95).
 Kostenberger, 39.
 Carson, 97.
 Kostenberger, 40.
 Ibid, 41.
 Carson, 99.
 Kostenberger, 42.
 Carson, 97.