MEN AND WOMEN ARE DIFFERENT AND EQUAL
Why the priesthood is reserved only for men, and not for women, and why that does not mean women are "less than".
The dogmatic constitution of the Second Vatican Council (1962-1965), the Lumen Gentium (‘Light of the People’, Latin) affirmed the fact that the priesthood has always and will always be reserved for men. Pope Leo XIV stated that the close connection between the sacrament of Holy Orders and the recipient’s male sex is deeply rooted in the Church’s hierarchical structure: it is not a human construct, but a divine institution. The Church is a divine institution “built upon the foundation of the apostles and prophets, Jesus Christ Himself being the chief cornerstone” (Ephesians 2:20). Once baptised, we all share in the priesthood of Christ, men and women alike, but the priesthood of Holy Orders is different, since it confers sacra potestas (‘sacred power’, Latin).
According to Canon 1379 §3 of the Code of Canon Law: Both a person who attempts to confer a sacred order on a woman, and the woman who attempts to receive the sacred order, incur a latae sententiae ("of a judgment having been brought", Latin) excommunication reserved to the Apostolic See; a cleric, moreover, may be punished by dismissal from the clerical state.
Not everyone is the same (obviously), but each and every one member of Christ’s Church has his/her own vocation and function within it (Romans 12:3–8). The Church has no authority to ordain a woman into the priesthood (only a baptised male can).
There are actual reasons [link] (shocking, I know) why this is so:
The Church’s constant tradition
The practice of the Apostles
Permanent Value of the Attitude of Jesus and the Apostles
The Ministerial Priesthood in the Light of The Mystery of Christ
The Ministerial Priesthood Illustrated by The Mystery of the Church
“The fact that there are things which a man is able to do but a woman is not, and vice versa, is rooted in the ontological difference between the two sexes as constituted by God. Although Galatians 3:27–28 states that “there is neither male nor female,” God created humanity as male and female, each with their own respective characteristics, features, and capacities (Gen 1:27–28; 5:2). Being “one in Christ” (Gal 3:28) signifies that all human beings have been equally redeemed through his sacrifice, just as there is no longer any distinction between Jews and non-Jewish people (cf. “there is neither Jew nor Greek” in the same verse). Moreover, the view that God wills the clear distinction between the two sexes to be maintained appears to be supported by the prohibition against men wearing women’s clothing, and vice versa (Deut 22:5).”
Thus, priesthood is reserved only for men. God created men and women with ontological differences. However, difference does not mean inequality. Everyone is fundamentally equal, with the same inviolable rights, and we all share in the redemption offered by Christ.