Alma 12:16 16 And now behold, I say unto you then cometh a death, even a second death, which is a spiritual death; then is a time that whosoever dieth in his sins, as to a temporal death, shall also die a spiritual death; yea, he shall die as to things pertaining unto righteousness.

Alma 12:17 17 Then is the time when their torments shall be as a lake of fire and brimstone, whose flame ascendeth up forever and ever; and then is the time that they shall be chained down to an everlasting destruction, according to the power and captivity of Satan, he having subjected them according to his will.

Alma 12:18 18 Then, I say unto you, they shall be as though there had been
no redemption made; for they cannot be redeemed according to
God’s justice; and they cannot die, seeing there is no more
corruption.

Alma 12:19 19 Now it came to pass that when Alma had made an end of
speaking these words, the people began to be more astonished;

Alma 12:20 20 But there was one Antionah, who was a chief ruler among them,
came forth and said unto him:  What is this that thou hast said,
that man should rise from the dead and be changed from this
mortal to an immortal state that the soul can never die?

Alma 12:21 21 What does the scripture mean, which saith that God placed cherubim and a flaming sword on the east of the garden of Eden, lest our first parents should enter and partake of the fruit of the tree of life, and live forever?  And thus we see that there was no possible chance that they should live forever.

Alma 12:22 22 Now Alma said unto him:  This is the thing which I was about
to explain, now we see that Adam did fall by the partaking of the
forbidden fruit, according to the word of God; and thus we see,
that by his fall, all mankind became a lost and fallen people.

Alma 12:23 23 And now behold, I say unto you that if it had been possible for Adam to have partaken of the fruit of the tree of life at that time, there would have been no death, and the word would have been void, making God a liar, for he said:  If thou eat thou shalt surely die.

Alma 12:24 24 And we see that death comes upon mankind, yea, the death which has been spoken of by Amulek, which is the temporal death; nevertheless there was a space granted unto man in which he might repent; therefore this life became a probationary state; a time to prepare to meet God; a time to prepare for that endless state which has been spoken of by us, which is after the resurrection of the dead.

Alma 12:25 25 Now, if it had not been for the plan of redemption, which was laid from the foundation of the world, there could have been no resurrection of the dead; but there was a plan of redemption laid, which shall bring to pass the resurrection of the dead, of which has been spoken.

Alma 12:26 26 And now behold, if it were possible that our first parents could have gone forth and partaken of the tree of life they would have been forever miserable, having no preparatory state; and thus the plan of redemption would have been frustrated, and the word of God would have been void, taking none effect.