Eliyahu on Har Hakarmel tells the story of how, in the times of the first Beis Hamikdash, a terrible drought spread throughout the land because of the avodah zarah of King Achav. The crops did not grow, and the Jewish nation suffered.
The people had to first do teshuvah in order to receive the much-needed rains. Eliyahu was given the all-important job of bringing the nation back to Hashem so that He could bless the land with rain once again.
