When Jesus was teaching of eternal life (Rich man and Lazarus, also Martha and Mary's brother Lazarus being raised from death) the people listening didn't think it was a new and novel idea: your soul lasts forever and you shall be judged.
Where is this taught in the Old Testament? I find Jesus telling the Saducees that "I am the God of Abraham, the God of Issac, and the God of Jacob", which is suggesting that Abraham, Issac and Jacob are not dead and gone (I was the God of Abraham, etc.).
Are there other places where it's made plain?