You are correct to say it is not that simple. The Church does not assert that those who reject the Church’s teaching on abortion are not Catholic. What the Church says is that they are not in full communion, or unity, with the Church.
This excerpt from Bishop Tobin’s letter to Kennedy more fully explains it:
(you write) The fact that I disagree with the hierarchy on some issues does not make me any less of a Catholic. Well, in fact, Congressman, in a way it does. Although I wouldnt choose those particular words, when someone rejects the teachings of the Church, especially on a grave matter, a life-and-death issue like abortion, it certainly does diminish their ecclesial communion, their unity with the Church. This principle is based on the Sacred Scripture and Tradition of the Church and is made more explicit in recent documents.
For example, the Code of Canon Law says, Lay persons are bound by an obligation and possess the right to acquire a knowledge of Christian doctrine adapted to their capacity and condition so that they can live in accord with that doctrine. (Canon 229, #1)
The Catechism of the Catholic Church says this: Mindful of Christs words to his apostles, He who hears you, hears me, the faithful receive with docility the teaching and directives that their pastors give them in different forms. (#87)
Or consider this statement of the Church: It would be a mistake to confuse the proper autonomy exercised by Catholics in political life with the claim of a principle that prescinds from the moral and social teaching of the Church. (Congregation for the Doctrine of the Faith, 2002)
Theres lots of canonical and theological verbiage there, Congressman, but what it means is that if you dont accept the teachings of the Church your communion with the Church is flawed, or in your own words, makes you less of a Catholic.
But lets get down to a more practical question; lets approach it this way: What does it mean, really, to be a Catholic? After all, being a Catholic has to mean something, right?
Well, in simple terms and here I refer only to those more visible, structural elements of Church membership being a Catholic means that youre part of a faith community that possesses a clearly defined authority and doctrine, obligations and expectations. It means that you believe and accept the teachings of the Church, especially on essential matters of faith and morals; that you belong to a local Catholic community, a parish; that you attend Mass on Sundays and receive the sacraments regularly; that you support the Church, personally, publicly, spiritually and financially.
Congressman, Im not sure whether or not you fulfill the basic requirements of being a Catholic, so let me ask: Do you accept the teachings of the Church on essential matters of faith and morals, including our stance on abortion? Do you belong to a local Catholic community, a parish? Do you attend Mass on Sundays and receive the sacraments regularly? Do you support the Church, personally, publicly, spiritually and financially?
In your letter you say that you embrace your faith. Terrific. But if you dont fulfill the basic requirements of membership, what is it exactly that makes you a Catholic? Your baptism as an infant? Your family ties? Your cultural heritage?
Your letter also says that your faith acknowledges the existence of an imperfect humanity. Absolutely true. But in confronting your rejection of the Churchs teaching, were not dealing just with an imperfect humanity as we do when we wrestle with sins such as anger, pride, greed, impurity or dishonesty. We all struggle with those things, and often fail.
Your rejection of the Churchs teaching on abortion falls into a different category its a deliberate and obstinate act of the will; a conscious decision that youve re-affirmed on many occasions. Sorry, you cant chalk it up to an imperfect humanity. Your position is unacceptable to the Church and scandalous to many of our members. It absolutely diminishes your communion with the Church.
Congressman Kennedy, I write these words not to embarrass you or to judge the state of your conscience or soul. Thats ultimately between you and God. But your description of your relationship with the Church is now a matter of public record, and it needs to be challenged. I invite you, as your bishop and brother in Christ, to enter into a sincere process of discernment, conversion and repentance. Its not too late for you to repair your relationship with the Church, redeem your public image, and emerge as an authentic profile in courage, especially by defending the sanctity of human life for all people, including unborn children. And if I can ever be of assistance as you travel the road of faith, I would be honored and happy to do so.
An excellent and thoughtful reply. Thank you.