Bible Study Seattle

Evidently, Gehenna and the lake of fire are not exactly the same thing, although Gehenna flows into the lake of fire.
“And if thy foot may cause thee to stumble, cut it off; it is better for thee to enter into the life lame, than having the two feet to be cast to the gehenna, to the fire — the unquenchable –“. Mark 9:45
“and the Devil, who is leading them astray, was cast into the lake of fire and brimstone, where [are] the beast and the false prophet, and they shall be tormented day and night — to the ages of the ages.” Revelation 20:10

The valley of Hinnom southwest of Jerusalem is Gehenna, which is a ravine that flows about fifteen miles east into the Dead Sea, which is the lake of the fire. For the last 200+ years this lake has not been on fire, but prior to that it periodically burned from the bottom and smoldered. Evidently, sometime in the future it will burn again. The nature and timing of these dreadful judgments are still under great debate today.