Jesus is God
John described Jesus the BEST in John 1:1-14
In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through him all things were made; without him nothing was made that has been made. In him was life, and that life was the light of men. The light shines in the darkness, but the darkness has not understood it. There came a man who was sent from God; his name was John. He came as a witness to testify concerning that light, so that through him all men might believe. He himself was not the light; he came only as a witness to the light. The true light that gives light to every man was coming into the world. He was in the world, and though the world was made through him, the world did not recognize him. He came to that which was his own, but his own did not receive him. Yet to all who received him, to those who believed in his name, he gave the right to become children of God— children born not of natural descent, nor of human decision or a husband's will, but born of God. The Word became flesh and made his dwelling among us. We have seen his glory, the glory of the One and Only, who came from the Father, full of grace and truth.
Christ is more than a system, tradition, or belief. He is a Person who knows our needs, feels our pain, and sympathizes with our weakness. In exchange for our trust, He offers to forgive our sins, to intercede for us, and to bring us to His Father. He cried for us, died for us, and rose from the dead to show that He was all He claimed to be. Conquering death, He showed us that He can save us from our sins, live His life through us on earth, and then bring us safely to heaven. He offers Himself as a gift to anyone who will trust Him (John 20:24-31).
So yes, HE KNEW everything.
One example: John 1:47-49
When Jesus saw Nathanael approaching, he said of him, "Here is a true Israelite, in whom there is nothing false." "How do you know me?" Nathanael asked. Jesus answered, "I saw you while you were still under the fig tree before Philip called you." Then Nathanael declared, "Rabbi, you are the Son of God; you are the King of Israel."
Nathanael KNEW that Jesus is God when Jesus told him what He knows about him that no one else knows but God.