We have seen that God chose Mary to bring his only Son into the world and bestowed upon a woman the great dignity of becoming the Mother of God.
In our times there has arisen a debate concerning the ordination of women to the priesthood. This is not the first time in the history of the Church that the question has arisen and each time the answer has been "No!" Epiphanius of Salamis writes, "Certain women there in Arabia [the Collyridians] ... In an unlawful and blasphemous ceremony ... ordain women, through whom they offer up the sacrifice in the name of Mary. This means that the entire proceeding is godless and sacrilegious, a perversion of the message of the Holy Spirit; in fact, the whole thing is diabolical and a teaching of the impure spirit." (Against Heresies 78:13 [A.D. 377] )
The question is, "Why Not?"
Peter Kreeft in a lecture on "Women and the Priesthood" given at the Franciscan University of Steubenville - 1994, has spelled out the universal principles of masculinity and femininity involved. In what fellows, I summarize.
In creating the world God has embodied the principles of masculinity and femininity, that is the play of opposite (Yin-Yang) at all levels of realty. For example, the sun has a masculine character because its energetic rays are outgoing while the earth is feminine because it receives the sun's rays and brings and brings forth life. On the biological level man and woman are the individuated expressions of these universal principles. But, in God there is no duality but a unity of Father, Son and Spirit.
That the Jews express the reality of God as He, or in the masculine, is no accident but intended by God. God is the creator who creates from nothing, from outside. He goes out toward men and seeks them out and the wills law which we must obey. The Jews were to choose only the first born males of the tribe of Levy to becomes priests unlike pagan nations who also had female priests. At the appointed time God sent his Son into the world as a man, not a woman. In this way the Father defines his masculinity, that is, His outgoing character which is also present in the nature of man. It is man who impregnates woman, not the other way around. Man is a living symbol of God's masculinity.
Christ is the "Image of the invisible God" (Col 1:15) and as the image of the Father must reflect the masculinity of the Father. Christ chose only men to represent him. Christ risen from death is eternally the God/Man before the Father and this reality cannot be changed. Only men, therefore, can represent Christ, woman cannot due to her receptive nature.
Although Peter Kreeft does not point this out, there is another perspective which reveals the relationship of God toward mankind. Let us suppose that God sent a woman into the world to redeem it. We would have a Virgin Mother and a Divine Daughter. In this scenario the male gender would have been left completely out from the order of salvation. We may further observe that Christ does not refer to the first person of God as "Mother". If he had done so, Christ would have had two mothers, God and Mary, but not father eiher divine or human since Joseph did not give him life.
Gertrud von le Fort in her book The Eternal Woman makes the following profound observation, "In her character as mother, the Church is the cooperating principle; the One who works within her is Christ himself. Here lies the fundamental reason why it was fitting that the priesthood was never entrusted to woman. ...The priesthood could not be confided to woman, for thereby the very meaning of woman in the Church would have been annihilated. A part of the essential nature of the Church of which woman is the symbol would likewise have been annihilated."
To this day the Church affirms this view of reality. The Pope has no power to allow women priests because this is not in the nature of God and the plan of God for the salvation of mankind. Further, the Church prohibits the ordaining of women to the priesthood under the penalty of excommunication as follows: "...both the one who attempts to confer a sacred order on a woman, and the woman who attempts to receive a sacred order, incur an excommunication latae sententiae reserved to the Apostolic See." (General Decree of the Congregation for the Doctrine of the Faith)