The most memorable steak I ever ate was cooked over a campfire in Michigan. The meat was suspended over fire with some salt sprinkled on it. I have not tasted a more flavourful piece of beef.

When animal sacrifices were performed, the priest would salt the meat before roasting it on the altar. The salt releases flavour when the heat of the fire is applied. 

Hell fire may be the outcome of a corrupted life, but God also uses fire in our lives to bring out a pleasing flavour and aroma.

Gehenna was a burning dump outside the walls of Jerusalem. It's also a name Jesus sometimes used in reference to the eternal fire of punishment. 

Jesus contrasted the fire of hell with the fire of sacrifice. Hell is a garbage fire where corruption goes, but the fire of God is applied to our refinement. The altar is a cooking fire where the best qualities emerge.

Mark 9:
49 Everyone will be salted with fire.
50 “Salt is good, but if it loses its saltiness, how can you make it salty again? Have salt among yourselves, and be at peace with each other.”

Mark is saying that we need to be seasoned by God in the fiery trials that are set beneath us. God brings out a good flavour and aroma so that we can participate in reconciled relationships.

It is really a dramatic choice for us to make. Remain disconnected from God with an infection that never leaves our soul, or let the Great Physician remove the corrupted flesh from us and live in peace.

Strong warnings from Jesus are always countered with the strong hope of salvation.