Problem: John mentions numerous times that Jesus said “I Am” (e.g., John 6:35; 8:58; 10:9; 14:6). Yet not one of these statements is mentioned in any other Gospel. Did John make these up, or did Jesus actually say them?
Solution: John reported accurately what he heard and saw. First of all, he was an eyewitness of the events (John 21:24; cf. 1 John 1:1). His Gospel is filled with details of geography (3:23), topography (6:10), and private conversations that betray a first-hand, first-century knowledge of the events (cf. John 3; 4; 13–17).
Further, when John records events and/or conversation found in the other Gospels, he does so in substantially the same way they do. This includes the preaching of John the Baptist (1:19–28), the feeding of the 5,000 (6:1–14), Jesus’ walking on the water (6:15–21), eating the Passover with His disciples (13:1–2), Peter’s denial (13:36–38; 18:15–27), Judas’ betrayal (18:1–11), His trials (18–19), His crucifixion (19), and His resurrection (20–21).
In addition, the other Gospels record some of the same types of conversation recorded in John. Matthew 11:25–30 sounds like something right out of the Gospel of John. Even Jesus’ characteristic use of “verily” (kjv), (“truly,” nasb; “assuredly,” nkjv) in John (cf. 1:51; 3:3, 11; 5:19, 24, etc.) is found in other Gospels (cf. Matt. 5:18, 26; Mark 3:28; 9:1; Luke 4:24; 18:17), though John alone doubles it perhaps for emphasis.
Finally, John’s differences from the synoptics can be accounted for in several ways. First of all, John writes primarily about Jesus’ Judean ministry, whereas the other Gospels speak largely about His Galilean ministry. Second, John records many of Jesus’ private conversations (cf. chaps. 3–4; 13–17), whereas the other Gospels speak mostly about His public ministry. Third, clear “I Am” statements come usually after Jesus has been challenged and He declares His point simply and emphatically. Even so, they are not without parallel in the other Gospels, where Jesus says “I am” [the Christ] (Mark 14:62).