Women already act as other Christs
As adopted children of God, women as well as men, are images of Christ
God's Word links both sexes when speaking of divine resemblance: 'God created man in the image of himself; in the image of God he created him; male and female he created them' (Genesis 1, 27). And St Paul says that all, men and women, have put on Christ (Galatians 3, 27). He speaks of all christians when he says, 'We, with our unveiled faces reflecting like mirrors the brightness of the Lord, all grow brighter and brighter as we are turned into the image that we reflect; this is the work of the Lord who is Spirit' (2 Corinthians 3, 18).
The reason for this is that, in and through Christ, we have become adopted children of God. To all who accepted him he [=Christ] gave power to become children of God (John 1,12). The Spirit himself and our spirit bear united witness that we are children of God (Romans 8,16). This applies to all, both men and women.
The equality of men and women arises from an equal putting on of Christ in baptism
When we ask the question: Is the relation of a female to Jesus as the Christ essentially different from the relation of a male to Jesus as the Christ? tradition has a great deal to say of a fairly direct sort, if not by way of extended theological reflection, then at any rate by way of practice. Most important in this connection is the simple and obvious fact that women are baptized; and that this sacramental action establishes them in a certain relation to God in Christ. What is this relation and what are its implications for understanding the role of women in the Church?
The relationship to Christ which baptism seals is not merely one in which the faithful person receives from Christ a gift which is distinct from and external to the giver. It may be said, and properly said, that baptism confers forgiveness of sins or the grace of justification. It is apparent, however, in the light of New Testament understandings of baptism, that such gifts belong to the baptized person in virtue of the fact that he or she is joined to Christ, puts on Christ, becomes a member of Christ, is buried with Christ, and so on. To be baptized is to be so associated with Christ in the power of the Spirit that one shares in his relationship to the Father. God sent the Spirit of his Son into our hearts crying Abba, Father (Galatians 4,6). Hence Cyril of Jerusalem observed that the meaning of baptism is simply sharing in the sonship of Christ, as well as in his death, his resurrection, and his power to conquer evil (Catechetical Oration III, passim).
It is obvious from these considerations that the custom of baptizing women has implications for the problem of women representing Christ at the Eucharist. That custom does not merely imply a belief that women may be saved, i.e. that their sins are forgiven or that they are proper recipients of sanctifying grace. It entails also the belief that women can and in fact do share the identity of Jesus as the Christ, that they are incorporated in him, as in the representative of the human race, and that in consequence Christ lives in them. So it must be said that baptism establishes women, as it does men, in the role of representatives of Christ - persons in whom the reality of the Christ-life, of at-one-ment with God, is symbolically manifested. The logical implication is that women, as much as men, can represent Christ also at the Eucharist.
No one has explained this better than R.A. Norris.
As far as the meaning of baptism is concerned, then, women have the same relation to God-in-Christ as men. Moreover this relationship constitutes them not merely as beneficiaries of salvation, but as sharers in the identity of Christ - which means his sonship, and therefore his servanthood, his priesthood, and his prophetic and royal offices vis-à-vis the world. That they do not and cannot share the maleness of Jesus is, apparently, no obstacle to this relationship or to the ministry which it involves - and for good reason, as we have seen, since it is Christs humanity, and not his maleness, in virtue of which he is God-with-us. Baptismal practice and christological doctrine here reinforce each other.
But what does all this have to do with ordination? For ordination is not baptism. It is another sacrament altogether, and presumably therefore the fact that women are baptized says nothing in itself about whether or not they may be ordained . . .
It is true, of course, that ordination is another sacrament, and that it establishes a person not as a forgiven and justified member of Christ, but as one who stands in a certain relation to the Church - a relation which constitutes the minister a sacramental person signifying the presence of the divine Word by which the Church lives. Nevertheless it must be asked what apart from ordination itself, is required in order that a person may truly fulfil this sacramental role in relation to the Church? Furthermore, in asking this question one must keep in mind that while there are indeed more sacraments than one, they differ among themselves not in what they ultimately signify, but in the manner in which and the purpose for which they signify it. The grace and truth which are in the Word Incarnate are one . . .
One requisite for ordination is, and always has been, baptism, . . . but is maleness also a necessary condition for ordination? It is at this point that the relevance of a discussion of baptism to the question of the ordination of women becomes apparent. The fact that women are baptized; that baptized women are in Christ and share his identity; that in virtue of this identity they exercise a lay ministry which involves the imaging and representation of Christ in and for the world - these facts create a presumption that they are also capable of representing Christ in the role of an ordained person. The presumption is further strengthened when it is recognized that the identity in which Christ is represented to world and Church as their salvation is not that of a male, but that of humanity as bearer of the divine Word. The New Creature is not constituted by maleness; and there is therefore no reason to suppose that maleness is required for its imaging.
Thus in the last resort the question boils down to this: Is it the Christ of the baptismal mystery whom the ordained person represents, or a Christ who is in fact otherwise understood and qualified? The Christ of the baptismal mystery - the Christ in whom the new order of creation is embodied and effected - is one in whom male and female, Jew and Greek, slave and free, share a single identity. Furthermore it is this Christ, and not another, whom the christological tradition clearly sets forth, by its insistence on the integral and inclusive humanity of the Word. To insist, then, that ecclesial priesthood must be male if it is to represent Christ, is to argue that ecclesial priesthood represents a different Christ from the one which the other sacraments of the Church embody and proclaim.
R.A.Norris, The Ordination of Women and the Maleness of the Christ, The Anglican Theological Review, June 1976; also in Feminine in the Church, ed. by Monica Furlong, SPCK, London 1984, pp. 71-85; here pp. 80-83.
In the administration of Baptism and Marriage, women act in the person of Christ
It is common sacramental doctrine that the minister of the sacraments acts as vicar of Christ. With regard to the validity of baptism, it is the explicit teaching of the Church that anyone with the use of reason, having the right intention and employing due matter and form, may be the minister of this sacrament and the minister, male or female, acts in persona Christi.
By his power Christ is present in the sacraments, so that when a person baptizes it is really Christ himself who baptizes. Vatican II, Sacrosanctum Concilium, § 7.
The ministers of the sacrament of matrimony are the partners themselves. As Pius XII succinctly expressed it in Mystici Corporis: The spouses are ministers of grace to each other (Acta Apostolicae Sedis 35 (1943) p. 202). The sacrament of matrimony is a permanent sacrament. Consequently, as long as the marriage lasts the spouses remain ministers of Christs love and grace to each other.
The sacraments are the acts of Christ. Therefore in respect of baptism, given the conditions mentioned, a pagan woman can be the minister and in such a case she acts in persona Christi, it is Christ who baptizes. In regard to matrimony, the woman who becomes wife and the man who becomes husband remain permanent ministers of sacramental grace and, to accommodate the words of St. Augustine: When a man marries, it is Christ who marries; when a woman marries, it is Christ who marries (In Iohannis Evangelium VI; PL 35, 1428).
Eric Doyle, The Question of Women Priests and the Argument In Persona Christi, Irish Theological Quarterly 37 (1984) pp. 212 - 221, here pp. 215 - 216.