One of the number one searches on the topic of hell on the internet is "Is hell eternal?" followed closely by "How can a loving God condemn people to hell?"
Well, Biblically speaking, the only word that matters is the Greek word aionios
This word has had questionable standing for years and years, yet still very consistently gets translated as eternal.
However, Strong's concordance, one of the most respected Biblical language resources in the world, does not explicitly assign the word eternal to the Greek aionios
In fact, it puts a lot of emphasis on being that which "pertains to an age" or simply "agelong".
It also mentions it can be describing the quality of existence in said age.
So, assigning the word eternal to the Greek aionios is oversimplifying, to say the least.
Personally I put more stock in the agelong definition.
So one can actually read the Bible and have no mention about eternal punishment, but simply agelong punishment (or correction).
In fact, some translations, that boast of being literal, do translate this Greek word as age abiding or age lasting. So there are translations of the Bible that do not speak of eternal hell at all.