Nathanael expressed surprise in John 1:
On the other hand, Peter declared a propositional truth in Matthew 16:
The two incidents were rather different kinds of experiences from Nathanael and Peter's points of view. They both received special revelations from God but in different manners of experiences. The source of knowledge was the same, but the methods of delivery were different.
Apparently, Nathanael had a moment of personal quiet time with God under the fig tree just between him and God.48 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 was impressed that Jesus knew that particular moment and concluded that Jesus had to be God's Son to know that.49Nathanael answered Him, 'Rabbi, You are the Son of God; You are the King of Israel'”
On the other hand, Peter declared a propositional truth in Matthew 16:
Jesus explained the source of Peter's knowledge as a matter of fact/proposition.16 Simon Peter answered, 'You are the Christ, the Son of the living God.'
17 And Jesus said to him, 'Blessed are you, Simon Barjona, because flesh and blood did not reveal this to you, but My Father who is in heaven.'
The two incidents were rather different kinds of experiences from Nathanael and Peter's points of view. They both received special revelations from God but in different manners of experiences. The source of knowledge was the same, but the methods of delivery were different.