Then shall he say also unto them on the left hand, Depart from me, ye cursed, into everlasting fire, prepared for the devil and his angels - Mt. 25 :31
The fire is everlasting, but it does not say those thrown in it are.
And fear not them which kill the body, but are not able to kill the soul: but rather fear him which is able to destroy both soul and body in hell. Mt. 10: 28
This says that the soul dies. If something is destroyed, it no longer exists.