The wages of sin is death. Everlasting fire, eternal fire are fires that consume – burn things to nothing. Gone forever, everlastingly gone, eternally disappeared. That is the same as eternal punishment. These terms: everlasting and eternal show a deep expression of continued existence or disappearance.
Everlasting life is the opposite to everlasting punishment. One lives forever, the other die forever. The so called “dogs” and “goats” will inherit eternal punishment, while the so called “sheep” will inherit eternal life – If Jesus said so, so will it be.