In a sense, the disciples have known Jesus. They spent the past couple of years living with Him, listening to Him teach, seeing Him heal the sick, talking with Him, and just spending quality time with Him. They knew Him well enough, even in the beginning of their discipleship, to leave their families, businesses, and homes to follow Him. But they still didn’t know Him in the fullness of what that means. Up till now everything has been preparation. They still do not have a full knowledge of Jesus and His significance, but things are about to change. From now on they will not only know God, but they will also “see” Him in a figurative sense (John 1:18).

John 1:18  No-one has ever seen God, but God the One and Only, who is at the Father’s side, has made him known.

Dodd has pointed out that throughout the whole Old Testament it is very rare that anyone has claimed to know God as in (Psalms 36:10). A knowledge of God is looked for as a future blessing when the Law will no longer be written on tablets of stone, but on men’s hearts. No longer will men need to admonish others to know the Lord, for they will all know Him, from the least of them to the greatest (Jer 31:31-34). Jesus sees this whole situation as completely changed. Because of what Christ did for us on the cross, an intimate knowledge of God is supposed to be the norm for the Christian today. The substitutionary death of Christ brought about the fulfillment of the prophecy in Jeremiah and we are now lving under that new covenant where we really do know God personally. “From now on, you do know him and have seen him.”

Psalms 36:10  Continue your love to those who know you, your righteousness to the upright in heart.

Jeremiah 31:31-34  “The time is coming,” declares the LORD, “when I will make a new covenant with the house of Israel and with the house of Judah.
  It will not be like the covenant I made with their forefathers when I took them by the hand to lead them out of Egypt, because they broke my covenant, though I was a husband to them,” declares the LORD.  “This is the covenant that I will make with the house of Israel after that time,” declares the LORD. “I will put my law in their minds and write it on their hearts. I will be their God, and they will be my people.  No longer will a man teach his neighbour, or a man his brother, saying, ‘Know the LORD,’ because they will all know me, from the least of them to the greatest,” declares the LORD. “For I will forgive their wickedness and will remember their sins no more.”

A true Israelite, one who is upholding the covenant of God, is one in whom there is no guile. “guile” (KJV) = dolos = bait for catching fish; therefore any cunning contrivance for catching or deceiving.  The term was used by the Greeks for, among other things , the Trojan horse. Biblically it is used of Jacob before his conversion; in fact, one translator renders this part of the verse as “an Israelite in whom there is no Jacob.” (Temple)  Having no deceit or guile was also an attribute of the Messiah (Isaiah 53:9) and is an attribute of one who is blessed of the Lord (Psa 32:2). Why did Jesus place such store in this quality?

Isaiah 53:9  He was assigned a grave with the wicked, and with the rich in his death, though he had done no violence, nor was any deceit in his mouth.

Psalms 32:2  Blessed is the man whose sin the LORD does not count against him and in whose spirit is no deceit.

Note that Jesus only praises Nathanael, and does not say a word about his doubts or prejudices. Jesus does not condemn us (John 8:11). He is always looking for the good in us and when He finds it; he encourages us with it and even brags about us to others. Jesus only has good words for us or words that are good for us.Joh 8:11  “No-one, sir,” she said. “Then neither do I condemn you,” Jesus declared. “Go now and leave your life of sin.”