Unless a person die and come back to life, it would be impossible to prove that this person's life was indeed eternal. For without the resurrection, it would take an eternity to prove that his life was eternal. Even if He could survive in the heart of the sun, that wouldn't prove that he could eventually die of some sort of other destruction or that the sun wouldn't eventually kill him. But if he should die and come back to life of his own accord, then you know that death can't destroy Him. And if death can't destroy Him, then you know that his life is eternal. For there is either life or death; you cannot have both. So if you cannot remain dead, then you will always live.