Why Did the Apostles Have to Die?

Why weren't the apostles translated like Elijah? Surely they would have qualified for that.

And it came to pass, as they still went on, and talked, that, behold, there appeared a chariot of fire, and horses of fire, and parted them both asunder; and Elijah went up by a whirlwind into heaven.
- 2 Kings 2:11 (KJV)

I think the main reason is that their deaths added credibility to their testimony.

And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death.
- Revelation 12:11 (KJV)

Some people have suggested that the apostles made it all up, but clearly they stuck with their testimony even unto their own death. Would you die for a lie?

One after another the foremost of the builders fell by the hand of the enemy. Stephen was stoned; James was slain by the sword; Paul was beheaded; Peter was crucified; John was exiled. Yet the church grew. New workers took the place of those who fell, and stone after stone was added to the building. Thus slowly ascended the temple of the church of God.
- Ellen White, The Acts of the Apostles, p. 597

Courage and fortitude were given to them as required.

The disciples were not endowed with the courage and fortitude of the martyrs until such grace was needed.
- Ellen White, The Desire of Ages, p. 354

I find that very reassuring.