Hell equals death. Jesus taught life eternal or death eternal. The gospel writers or later translators used hell for eternal death.
Jesus would have spoken the common language of the day which was Aramaic.
English "Gehenna" represents the Greek Geenna (Γέεννα) found in the New Testament, a phonetic transcription of Aramaic Gēhannā (ܓܝܗܢܐ), equivalent to the Hebrew Ge Hinnom, literally "Valley of Hinnom".
There is no such animal as "eternal" death. Our God is indeed aidios from which everything flows unto His purposes in the Christ.
Aidios kolasis is NOT mindless torture but one of change and transformation!
God is the Source, Guide & Goal of ta panta