No one ever said that Jesus is not the Son of God, but the office of the Son has been fulfilled. Big difference.
He's called the Son of God one time in Chapter 2 of the book of Revelation, and through the rest of the book He's called "pantokratōr" THE ALMIGHTY. The Son of God was born of the Holy Ghost to Mary
Luke 1:35, and
Galatians 4:4, but when He was glorified the office of the Son was fulfilled. Not that there was no Son or any of those things, because to come to the Father you have to come through the Son. But the purpose and the plan of the Son was fulfilled on Calvary's hill and His ressurection and Ascension when He came into the Tabernacle not made by man's hand, and the blood of His sacrifice was set before God.
Hebrews 9:24-26 KJVS
"For Christ is not entered into the holy places made with hands, which are the figures ae of the true; but into heaven itself, now to appear in the presence of God for us: [25] Nor yet that he should offer himself often, as the high priest entereth into the holy place every year with blood of others; [26] For then must he often have suffered since the foundation of the world: but now once in the end of the world hath he appeared to put away sin by the sacrifice of himself."
Though the office of the Son is fulfilled, there's no way of Salvation outside the Son. His blood and sacrifice stands before God from now until the end of this present world.