The recent trend towards equality and the interchangeability of the genders has prompted calls for women’s ordination. If men and women are truly equal in the sight of God, why can’t women be priests?
The question of "Why can't women be priests?" is flawed. All baptized Christian women are indeed priests.
When they are baptized, Christians are appointed with the triple office of priest, prophet, and king. The office of priest granted by the sacrament of baptism is part of the “common priesthood of all the faithful,” to be lived out in “a life of faith, hope, and charity.”
So Christian women can be priests – indeed, they are designated as priests through their very baptism, sharing in the common priesthood of the faithful. However, they cannot be ordained to the ministerial priesthood, granted by the sacrament of Holy Orders.
This raises the question of why women can’t be ordained to the ministerial priesthood in the Catholic Church. After all, women are quite capable of dedicated service to God - why can’t they serve God on the altar?
The answer is deceptively simple, depending on the reality that the genders are not interchangeable. Men and women were created by God equal in dignity, but with very different roles to play.
Just as there are certain things men cannot do by their very nature as man that women can do (i.e., give birth) so too there are certain things women cannot do by their very nature as women that men can do.
The Roman Catholic priesthood falls into this category. The Catholic priest is an “alter Christus” – to be another Christ. When presenting the sacraments to the faithful, the priest quite literally takes the place of Christ.
Christ came to this earth as a man – he did not come as a woman. The role of the alter Christus demands that the practitioner be a man – as Christ was a man, so too must those taking the place of Christ be.
Thus, while all baptized men and women are priests, only men can be ordained to the ministerial priesthood.