"The following day Jesus wanted to go to Galilee, and He found Philip and said to him, 'Follow Me.' Now Philip was from Bethsaida, the city of Andrew and Peter. Philip found Nathanael and said to him, 'We have found Him of whom Moses in the law, and also the prophets, wrote--Jesus of Nazareth, the son of Joseph.' And Nathanael said to him, 'Can anything good come out of Nazareth?' Philip said to him, 'Come and see'" (John 1:43-46).
Jesus desires to go to Galilee. In what would become His customary way, He invites Philip to become one of His disciples by saying, "Follow Me" (cf. Matt. 9:9; Luke 9:59; etc.).
Philip is the third witness mentioned in this book thus far, and he speaks with Nathanael. Nathanael is commonly identified as Bartholomew for the following two reasons: (1) "Nathanael" is found in the book of John but not in the other gospel accounts; "Bartholomew" is found in the other gospel accounts but not in John & (2) "Bartholomew" is not a proper name, but a patronymic name: Bar-Tholmai = son of Tholmai (like Simon Bar-Jonah in Matthew 16:17 means Simon, son of Jonah; cf. John 1:42).
Anyway, Philip testified to Nathanael, "We have found Him of whom Moses in the law, and also the prophets, wrote - Jesus of Nazareth, the son of Joseph." Where did Moses wrote of Christ? - Genesis 3:15; 49:10; Deuteronomy 18:15-19. Where did the prophets write of Christ? - II Samuel 7:12-16; Isaiah 7:14; 9:6; 42:1; 52:13; 53:1-12; Daniel 7:13; Micah 5:2; Zechariah 9:9; etc. (cf. John 5:39). We could spend a great deal of time considering these passages (and others) that testify of Christ, but that is beyond the scope of our present study. The interested reader is encouraged, of course, to study these passages in context.
Nathanael was certainly familiar with what Moses and the prophets wrote about Christ but is nonetheless skeptical of Philip's claim - "Can anything good come out of Nazareth?" The text does not reveal why this village is so despised. Philip unargumentatively invited him to "come and see." Any individual, like Nathanael, who is genuinely seeking the truth will carefully investigate all evidence (cf. Isa. 1:18; I Thess. 5:21). True investigation removes ignorance as well as prejudice.
"Jesus saw Nathanael coming toward Him, and said of him, 'Behold, an Israelite indeed, in whom is no deceit!' Nathanael said to Him, 'How do you know me?' Jesus answered and said to him, 'Before Philip called you, when you were under the fig tree, I saw you.' Nathanael answered and said to Him, 'Rabbi, You are the Son of God! You are the King of Israel!' Jesus answered and said to him, 'Because I said to you, "I saw you under the fig tree," do you believe? You will see greater things than these.' And He said to him, 'Most assuredly, I say to you, hereafter you shall see heaven open, and the angels of God ascending and descending upon the Son of Man'" (John 1:47-51).
Jesus' observation of Nathanael shows that He sees more than the outer man--He sees into the heart (cf. 2:25; I Sam. 16:7). Jesus says that Nathanael is an Israelite in spirit as well as in flesh. Nathanael's response shows his surprise at Jesus' statement, and he asks how Jesus knew him. Jesus replied that He had seen Nathanael under a fig tree before Philip had called him. Clearly, Nathanael was alone under the fig tree and he understands that Jesus must have gained this knowledge supernaturally.
Nathanael now becomes John's fourth witness by saying - "Rabbi, You are the Son of God! You are the King of Israel!" Here a true Israelite recognizes at once his true king. Any doubts Nathanael may have had concerning this Man from Nazareth have vanished! Nathanael regarded the revelation of his character and his whereabouts as a great thing, but he was destined to see greater things than these. This verse is a preview of the rest of the book: greater things will be seen!
Jesus' use of the word "you" in John 1:51 is plural, which would include all those who were present (and not just Nathanael exclusively). What does Jesus mean here in this verse? It is difficult to have absolute certainty here, but it seems that He is discussing the relationship of the supernatural to the natural. Jesus could be seen as the ladder (bridge or link) between the natural and supernatural (cf. Gen. 28:12; John 1:14). Mysteries from heaven will be revealed (opened) by messengers of God ("angels") by means of Christ. What those men had witnessed that day from Jesus was nothing much really; they hadn't seen anything yet!