Why should mankind believe in God?

The answer from God’s word:

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“God created all things, and so He makes all creation come under His dominion, and submit to His dominion; He will command all things, so that all things are in His hands. All creation of God, including animals, plants, mankind, the mountains and rivers, and the lakes—all must come under His dominion. All things in the skies and on the ground must come under His dominion. They cannot have any choice, and must all submit to His orchestrations. This was decreed by God, and is the authority of God. God commands everything, and orders and ranks all things, with each classed according to kind, and allotted their own position, according to God’s will. No matter how great it is, no thing can surpass God, and all things serve the mankind created by God, and no thing dares to disobey God or make any demands of God. And so man, as a creature of God, must also perform the duty of man. Regardless of whether he is the lord or ruler of all things, no matter how high man’s status among all things, still he is but a small human being under the dominion of God, and is no more than an insignificant human being, a creature of God, and he will never be above God. As a creature of God, man should seek to perform the duty of a creature of God, and seek to love God without making other choices, for God is worthy of man’s love.”

from “Success or Failure Depends on the Path That Man Walks” in The Word Appears in the Flesh