Not that it's needed now we seem to have reached universal agreement but I was reading something on the burning sulfur-lake that put it into a new perspective.
One of the verses looked at was Revelation 21:8
But cowards, unbelievers, the corrupt, murderers, the immoral, those who practice witchcraft, the idol worshipers, and all liars - their fate is in the fiery lake of burning sulfur. This is the second death.
The point was made that that sulfur in fire has long been used in traditional metallurgy to separate and purify gold from other metals.
And as regards the "second death" part, this could could be "death" in the way it is meant even in this life when we are called to die to self and to sin every day, and are said to have been baptized into Christ's death.
This verse was coupled with these other two about being salted with fire and the testing:
...if your eye causes you to stumble, tear it out; it is better for you to enter the kingdom of God with one eye than to have two eyes and to be thrown into Gehenna, where their worm never dies, and the fire is never quenched. For everyone will be salted with fire. Salt is good; but if salt has lost its saltiness, how can you season it? Have salt in yourselves, and be at peace with one another.
Mark 9:47-50
if anyone builds on the foundation with gold, silver, precious stones, wood, hay, straw the work of each builder will become visible, for the Day will disclose it, because it will be revealed with fire, and the fire will test what sort of work each has done. If what has been built on the foundation survives, the builder will receive a reward. If the work is burned up, the builder will suffer loss; the builder will be saved, but only as through fire.
1 Corinthians 3:12-15