Jesus saw Nathanael coming toward Him, and said of him, "Behold, an Israelite indeed, in whom there is no deceit!" Nathanael said to Him, "How do You know me?" Jesus answered and said to him, "Before Phillip 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!" John 1:47-49
This scripture reminds me of Matthew 7:21-23 where many were coming to Jesus saying they had prophesied, cast out demons and done many wonders in His name and Jesus told them, "I never knew you, depart from Me!"
In Nathanael's case however, Jesus said He knew him when He saw him under the fig tree. Nathanael or Bartholomew as his first name is listed in every instance where the disciples are spoken of, he being a scholar of the law and the prophets and a searcher of the scriptures was totally surrendered to the Lord Jesus Christ!
Nathanael preached the gospel as one of the most adventurous missionaries with Phillip in Phrygia and Hierapolis and also in Armenia where they claimed him as their founder and martyr. Tradition says he also preached in India where it is believed he died a martyr, being flayed alive with knives!
Jesus answered and said to Nathanael, "Because I said to you, I saw you under the fig tree, do you believe? You will see greater things than these." "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 1:50,51
Your servant in Christ, Timothy Laughlin