John 17:3
Now this is eternal life--that they know you, the only true God, and Jesus Christ, whom you sent.
Note carefully how Jesus defines "eternal life" and note he does not equate it to a period of time but a state of being.
The opposite of eternal life then, eternal death, is not about a period of time. It's complete separation from God.
Philosophically, eternity isn't really a time either.
So the point is to note that Jesus could suffer eternal death - separation - and yet be raised if he bridged that separation in the "price" (death) itself.
If "eternal" meant "forever" you would have a point. But does it? And what is "forever" anyway?
I believe if you want to engage by asking a good question, you ought to ask good questions of your own assumptions too

. So you need to question what you mean by "eternal life" and provide a definition for the discussion.