What Are the Purpose and Theme of the Gospel of John?

Faith in Christ for eternal life is central to John’s gospel, as his purpose statement reflects (20:30-31). The verb “believe” (pisteuo) is used about 100 times, with numerous synonyms of and symbols for “believe” such as “receive” (1:11), “know” (4:42; 6:69), “come to” (5:40; 6:35), “behold” (6:40), and “eat” and “drink” (6:54). Various other synonymous constructions include “believe in” (pisteuo eis) and “believe that” (pisteuo hoti). In the NT, the Fourth Gospel also presents the most extensive testimony that Jesus is the divine Son of God and prophesied Messiah.

While the Synoptic Gospels (Matthew, Mark, Luke) contain much parallel material, over 90 percent of John is unique. Unlike the Synoptics’, John’s unique content (e.g., woman at the well, Nicodemus) was designed primarily for evangelism (20:30-31). In the OT, God demonstrated perfection and completeness by mentioning a number plus one (Ps 62:11; Pr 6:16; Dn 3:24-25; Mc 5:5). Three Synoptic Gospels plus one (John) implies a complete but not exhaustive revelation of Christ. See also the sidebar, “A Comparison of the Synoptics and John.”