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 of 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.