Why does Hebrews 9:27 state what it does and yet Elijah and Enoch did not experience physical death?
"And as it is appointed for men to die once, but after this the judgment" (Hebrews 9:27).
The writer of Hebrews is stating a general principle. Because of Adam's sin, man is appointed to die. "In the sweat of your face you shall eat bread Till you return to the ground, For out of it you were taken; For dust you are, And to dust you shall return" (Genesis 3:19). But this general statement does not rule out exceptions. It doesn't state that every man must die once.
The point is being made that people just die once and not many times. Thus, when Jesus died, he only needed to die once to bring salvation to mankind. "So Christ was offered once to bear the sins of many. To those who eagerly wait for Him He will appear a second time, apart from sin, for salvation" (Hebrews 9:28).
Therefore, Hebrews 9:27-28 would be a good verse to prove that reincarnation is wrong. However, it doesn't prove that every person dies; after all, when Jesus returns those who are still alive do not first die. "For this we say to you by the word of the Lord, that we who are alive and remain until the coming of the Lord will by no means precede those who are asleep. For the Lord Himself will descend from heaven with a shout, with the voice of an archangel, and with the trumpet of God. And the dead in Christ will rise first. Then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air. And thus we shall always be with the Lord" (I Thessalonians 4:15-17). This, too, is an exception to the general rule.