2 Nephi 2:15

and to bring about his eternal purposes in the end of man, after that he had created our first parents, and the beasts of the field, and the fowls of the air, and in fine, all things which are created, it must needs be that there was an opposition; even the forbidden fruit in opposition to the tree of life; the one being sweet and the other bitter;

To complete his plan for people, he created our first parents. He created the animals in the field and the birds in the air. He created everything. There had to be opposites. The forbidden fruit was opposite to the tree of life. One was sweet and the other bitter.

To accomplish his eternal purposes for humanity, after he created our first parents and the animals of the field and the birds of the air—everything that exists—there had to be opposition. The forbidden fruit stood against the tree of life. One was sweet, the other bitter.