45 "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.” 46 Nathanael said to him, “Can anything good come out of Nazareth?” Philip said to him, “Come and see.” 47 Jesus saw Nathanael coming towards him and said of him, “Behold, an Israelite indeed, in whom there is no deceit!” 48 Nathanael said to him, “How do you know me?” Jesus answered him, “Before Philip called you, when you were under the fig tree, I saw you.” 49 Nathanael answered him, “Rabbi, you are the Son of God! You are the King of Israel!” 50 Jesus answered him, “Because I said to you, ‘I saw you under the fig tree’, do you believe? You will see greater things than these.” 51 And he said to him, “Truly, truly, I say to you, you will see heaven opened, and the angels of God ascending and descending on the Son of Man.”"
John 1:45-51
Nathanael, it seems likely, is the Bartholomew mentioned by the other gospel writers. He is mentioned here, and in 21:2, in a permanent position among the other disciples. There is no mention made in the Synoptists of the name Nathanael, just as there is no mention in John of the name Bartholomew. In the lists of apostles in Matthew 10:3, Mark 3:16, and Luke 6:14, Bartholomew is coupled with Philip's name. These considerations weigh heavily in bringing us to the conclusion we have about Nathanael's identity. We should note how well-informed scripturally Philip is. He is deeply taught in the Word and has already been able to interpret his experience in terms of a discovery of the long-promised Messiah. This surely bears witness to the value of one's early training in the Scriptures: when a true experience of Christ comes, all that we have learned lights up with new meaning and glory, and enables us to forge ahead spiritually. We should also note, however, the mistake Philip made in calling Jesus the son of Joseph. We know that he was not Joseph's son, but Philip did not know at this time (we are sure he learned it later). This should be an encouragement to us. It is quite conceivable, indeed inevitable, that a new believer should make serious mistakes in his theology while nevertheless having a genuine spiritual experience, and this should warn us against brushing aside or dismissing as of doubtful value a believer who cannot as yet dot all the 'i's' and stroke all the 't's' of our theological systems. Rome was not built in a day, and we ourselves did not attain theological orthodoxy in a day either.