unfortunately, since people often come up with their own gods, God has to go and prove that he is the one and only true God. Take 1st Kings ch. 18. The land is in a state of drought but here Elijah is pouring tons of precious water on the altar. Just read this... its classic.
1Ki 18:17-40
(17) And it came to pass when Ahab saw Elijah, that Ahab said to him, Is it you, the troubler of Israel?
(18) And Elijah said, I have not troubled Israel, but you and your father's house have, by forsaking the commandments of Jehovah, and following the false god Baal.
(19) And now go and gather to me all Israel to mount Carmel, and the 450 prophets of Baal, and the 400 prophets of the Asherah, who eat at Jezebel's table.
(20) So Ahab sent to all the children of Israel, and gathered the prophets together unto mount Carmel.
(21) Then Elijah drew near to all the people, and said, "How long do you waver between two opinions? if Jehovah be God, follow him; and if Baal, follow him". And the people answered him not a word.
(22) And Elijah said to the people, I, only I, remain a prophet of Jehovah; and Baal's prophets are 450 men.
(23) Let them therefore give us two bulls: and let them choose one bull for themselves, and cut it in pieces, and put it on the wood, and put no fire; and I will sacrifice the other bull, and put it on the wood, and put no fire.
(24) And you call on the name of your gods, and I will call on the name of Jehovah; and the god that answers by fire, let him be God. And all the people answered and said, That sounds good to us.
(25) And Elijah said to the prophets of Baal, Choose one bull for yourselves, and sacrifice it first; for you are the many; and call on the name of your god, but put no fire.
(26) And they took the bull which had been given them, and sacrificed it, and called on the name of Baal from morning until noon, saying, O Baal, answer us! But there was no voice, and none answered. And they leaped about the altar that had been made.
(27) And it came to pass at noon that Elijah mocked them and said, Cry aloud; for he is a god; for maybe he is deep in thought, or busy, or travelling, perhaps he is asleep, and will awake.
(28) And they cried aloud, and cut themselves after their manner with swords and spears, till the blood gushed out upon them.
(29) And it came to pass when midday was past, that they prophesied until the time of the offering up of the oblation; but there was neither voice, nor any that answered, nor any attention.
(30) Then Elijah said to all the people, Draw near to me. And all the people drew near to him. And he repaired the altar of Jehovah which was broken down.
(31) And Elijah took twelve stones, according to the number of the tribes of the sons of Jacob, to whom the word of Jehovah came saying, Israel shall be thy name;
(32) and with the stones he built an altar in the name of Jehovah, and made a trench round about the altar, of the capacity of two measures of seed;
(33) and he put the wood in order, and cut the bull in pieces, and laid it on the wood. And he said, Fill four pitchers with water, and pour it on the burnt-offering, and on the wood.
(34) And he said, Do it the second time. And they did it the second time. And he said, Do it the third time. And they did it the third time.
(remember, they are in a DROUGHT, trying to light the bull on FIRE)
(35) And the water ran round about the altar; and he filled the trench also with water.
(36) And it came to pass at the time of the offering up of the oblation, that Elijah the prophet drew near, and said, Jehovah, God of Abraham, Isaac and Israel, let it be known this day that you are God in Israel, and that I am your servant, and that I have done all these things by your word.
(37) Answer me, Jehovah, answer me, that this people may know that you, Jehovah, are God, and that you have turned their heart back again.
(38) And the fire of Jehovah fell, and consumed the burnt-offering, and the wood, and the stones, and the dust, and licked up the water that was in the trench.
(39) And all the people saw it , and they fell on their faces and said, Jehovah, he is God! Jehovah, he is God!
(40) And Elijah said to them, Seize the prophets of Baal; let not one of them escape! And they seized them; and Elijah brought them down to the torrent of Kishon, and slaughtered them there.
God is king, and he doesn't want anyone to usurp that power or position. Its rightfully His, because HE MADE EVERYTHING, among many other reasons. God made the times, he doesn't have to conform to the times.