God does not promise us anything of ultimate value which belongs to this fallen world which is passing away. Rest means eternal rest, because every human being has an eternal soul. It would not be rest if we were to lose it at the point of death. It would not be rest if the resting place was part of a world which will be burned up with fire. We must never lower our expectations of the reward of God to what is less than perfect. Our God is not weak in his ability to reward us.
This argument from the relative timing of various events and revelations shows how we must reason in interpreting Scripture. God never makes a promise in vain. He never holds out the hope of something which he does not sincerely intend to give. He never makes promises to the dead who are beyond the reach of grace and incapable of responding to the promise. God’s promises do not mock men and women. This allows us to rule out certain impossible interpretations of what he says in his word. We eagerly study the implications of all God has said and when he has said it, and we search diligently for every indication of his willingness to show us mercy. We hang on his every word, and come as those whose lives depend on his expressions of grace towards us.