John 1:51

And He saith unto him, Verily, verily, I say unto you, Hereafter ye shall see heaven open, and the angels of God ascending and descending upon the Son of Man.

Jesus wished to give Nathanael a practical demonstration of the truth of Philip's words. As he was approaching, the Lord said to those that were standing near Him, but so that Nathanael could hear His words: Behold in truth an Israelite, in whom guile is not. This man belonged to the small number of those in Israel that were members of God's people in truth, not merely by carnal descent, but by spiritual knowledge and faith. His hope was in the Messiah and His spiritual kingdom; he was free from guile and falsehood, the characteristic faults of the Jews. "Therefore Christ wants to say here also: There are true and false Israelites; the Israelites are of two kinds, which, indeed, are both descended from the patriarch Israel, but have not all kept the promise and the faith of Abraham. Just as there are now two kinds of Christians. We are indeed all called Christians who were baptized and regenerated through Baptism, but we do not all remain with our Baptism; many desert Christ and become false Christians, and the true Christians are few and far between. Thus there is also a true and a false Christian Church. And the false Christians boast that they are the true Church and true Christians; just as the Jews said they were the true Israelites; they boasted only of the title and name. Thus there are two kinds of Christians; first, those that have the name and are Christians in their body;... however, they do not remain with their Baptism, forgiveness of sins, and the promise of Christ, but separate themselves through false doctrines, desert the faith and the Lord Jesus Christ. But all true Christians, when they are baptized, hear the Gospel, read the Holy Scriptures, go to the Sacrament, love their neighbor. These make the right use of the Christian name and are truly Christians."

Nathanael was struck at once by this evidence of omniscience on the part of Jesus, and with surprise in his voice asked Him whence He knew him. And Jesus gave him evidence not only of His omniscience, but also of His omnipresence. Before Philip had approached his friend, while the latter was sitting in the shadow of the fig-tree, Jesus saw him. And everything was known to Him. The eyes of Jesus could easily read the heart and mind of Nathanael, who may have been meditating about the strange message of the Baptist, praying meanwhile that the day of the Messiah might soon come. All this Jesus knew. The Prophet of Nazareth, who knows the counsel of men's hearts, is an omniscient man. And Nathanael was obliged to acknowledge this, at the same time drawing the conclusion that Jesus is the Son of God, and that He is the true King of the spiritual Israel, of His Church. In Jesus all the prophecies of the Old Testament were fully realized; there could not be the slightest doubt as to His Messiahship. In Him God's reign in the hearts of the believers is realized; He rules over them that are His in grace and truth forever.

The open and unequivocal confession of Nathanael pleased the Lord, but it was not yet based upon a Bound enough foundation. A single demonstration of the divine power of Jesus is sufficient to work faith, but this faith must have the food from on high to feed upon, otherwise it will soon be starved. Jesus has greater things in store for His disciples, which He proceeds to tell them about with solemn emphasis. From now on, with the beginning of His public ministry, there would be a wonderful change for the believers. With His coming heaven itself is opened. The abyss of the Law has been removed, the enmity between God and man has been abolished, Ephesians 2:15. Instead of that, there is now direct communication between God and man, Jesus Himself being the Mediator. Something much more beautiful than the ladder of Jacob, Genesis 28:1, has now united earth and heaven the full atonement through the blood of the Savior. The angels of God are delighted to serve Him who came down for the salvation of the world. There is constant communication between Christ and His heavenly Father, in prayer, in miracles, and in other proofs of divine intimacy. And every bit of this work will be of benefit to all men, to be accepted by those that place their faith in their Savior.

Summary. After a prologue, giving a summary of the aims of the Gospel, the evangelist relates the story of the testimony of John the Baptist regarding Jesus, and tells of the gaining of the first disciples by this testimony: Andrew, John, Peter, Philip, and Nathanael.