Others beside us have their part also to do, and the perfection of the whole work depends upon their faithfulness as well as upon ours.

The best any of us can do in this world is but a fragment.

The old prophet thought his work had failed because Baalism was not yet entirely destroyed.

Then he was told of three other men, who would come after him--two kings and then another prophet, who each in turn would do his part, when at last the destruction of the great alien idolatry would be complete.

Elijah's faithfulness had not failed, but his achievement was only a fragment of the whole work.
This is very suggestive and very comforting.