Until Woman was created the “good” that was to be proclaimed about the world was not complete. The perfection of the world could never come about without Woman.
Our sages taught us that a without a wife a man cannot become a Man. Husband and wife in marriage can become אדם. See Commentary on נעשה אדם.
Man’s task is too great to accomplish alone. To accomplish this Woman was created for Man. The wording of the Torah expressing Woman’s role is עזר כנגדו, a helper beside him. Nowhere in this role is the notion of sexuality brought up. A woman is not to be the object of Man’s lust. Woman stands parallel to Man, standing beside him, with complete equality and independence, sharing mankind’s mission.
RSRH explains the inner meaning of the word עזר to mean one who helps in a way that relieves the person from some of his tasks, allowing him to focus on the remaining tasks more completely. (See his commentary here for a full explanation.)
God created a woman as opposed to creating another man, because the intention was to create a different kind of person, who would not duplicate the tasks of man, but rather have a different position than man. Mand and Woman compliment one another. Woman does not stand with Man but next to him. Each stands at a different point along the same line.
Beraishis 2:18, Pages 64-66
