One is not changing his mind when he changes his shirt. It just means he finished his work, and is now beginning another.
The Son did not begin a man, but He became one that He might have a gift and a sacrifice to offer as High Priest...not a levitical priest, not a jewish priest. A divine priest.
Judaism was a garment our High Priest wore for a time, to do a job given to him by the Father, but that time is long past, and that job has been done for millennia.
And in our glorified bodies, ancestry is gone. Go back to 1 Corinthians 15.
But some man will say, How are the dead raised up? and with what body do they come? Thou fool, that which thou sowest is not quickened, except it die: And that which thou sowest, thou sowest not that body that shall be, but bare grain, it may chance of wheat, or of some other grain: But God giveth it a body as it hath pleased him, and to every seed his own body. - 1 Corinthians 15:35-38
Behold, I shew you a mystery; We shall not all sleep, but we shall all be changed, In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed. For this corruptible must put on incorruption, and this mortal must put on immortality. - 1 Corinthians 15:51-53 KJV
We're not going to stay jews and gentiles. We will become the Sons of God.
To say Christians worship a Jew is like saying prize roses are grown to show off their seeds. It's also to say that Mary is still our God's mother.