Here is his question:
Several years ago my dad decided to come back to the Church (he had been Protestant ever since his family left the Church when he was a teenager) but my mother remained Protestant. Because they were married outside of the Catholic Church, their marriage had to be validated within the Church, since it was not completely valid in Her eyes. This is what aggravates my mom; she has always been faithful to her marriage and four children and then the Church says that it was never really valid because it wasn't a Catholic marriage, while my mom believes that it was completely valid.Yes, I can understand why she would be aggravated about that. Hopefully, my thoughts on this will be helpful.
The way I tried to explain this to her was comparing this teaching to the Church's teaching on the Sacrament of Confession. I told her that just as the Church believes you can't confess your sins directly to God but must confess them to an ordained Catholic priest who has been given the power by God to be His instrument and forgive the sins of the people, so too do you have to be married in the Sacrament of Holy Matrimony by an ordained priest who acts as God's instrument in establishing this marriage before God; that's why it had to be validated by the Church when my dad came back to the faith. This still doesn't convince her, of course, but I was wondering if this was the right way to explain it. Is there anything I missed, or is there something more to this teaching?Well, to be honest, I'm not entirely sure how to respond to her either. But, I do have some thoughts and maybe those will help.
Regarding the explanation that you gave your mom for why she would have to have her marriage validated by the Church, what you said was not quite right. As I understand it, the minister of the Sacrament of Matrimony is not actually the priest, it's the bride and the groom. In other words, the sacramental grace does not come from the priest. Instead, the grace comes from the bride and groom to each other, who have been empowered by God to be a source of strength for each other on their journey to heaven.
[someone please tell me if I'm wrong or if there is a better way to explain that]
The reason they need to be remarried in the Church is b/c it is only through the Sacrament of Matrimony in the Catholic Church that a covenant is made between man and wife that seals them together for all time. Sure, protestants receive grace too, and God was present at their marriage ceremony insofar as he is present in every place. But, through the Sacrament of Matrimony, you specifically call upon God to be a witness to your union, and you make a covenant oath to him and to your significant other that you will be faithful to this marriage for the rest of your life.
Also, it is only through the Sacrament of Matrimony that you receive the special grace (a grace particular to the sacrament) that God desires to give a couple so as to strengthen them to live long, faithful lives with each other. Marriage is not just a civil union proper to the state. It is a sacramental union and since a sacramental union did not take place, the Church cannot recognize it.
But, that does not invalidate the commitment that your parents have made to each other and to their children all these years. No one denies that they have been faithful in their marriage. All these years of commitment are not just down the drain. Your parents really are husband and wife (as far as the state is concerned). The Church simply wants to bring God and his grace into the picture in a more profound way (again, we acknowledge that God was present at their ceremony) so that their marriage can be blessed by God and the Church.
It's a good thing to be blessed by God and the Church! You can never have too much grace!
That's how I would begin to explain it to your mom. Again, these are just my thoughts and I guess I'm not 100% confident in what I have written here, but I think I'm on the right track. You can read some articles on the Sacrament of Matrimony for more information. Mark Curley's comment on this post is also helpful.