I understand that Catholics are required to obtain a dispensation to marry a non-Catholic; however, are there any regulations that concern practicing Catholics who wish to marry non-practicing Catholics (who have been baptized and confirmed)? Thanks!
Depends upon what you mean by “non-practicing.” From canon law:
Can. 1071 §1. Except in a case of necessity, a person is not to assist without the permission of the local ordinary at:
4/ a marriage of a person who has notoriously rejected the Catholic faith;
§2. The local ordinary is not to grant permission to assist at the marriage of a person who has notoriously rejected the Catholic faith unless the norms mentioned in ⇒ can. 1125 have been observed with necessary adaptation.
Can. 1125 The local ordinary can grant a permission of this kind if there is a just and reasonable cause. He is not to grant it unless the following conditions have been fulfilled:
1/ the Catholic party is to declare that he or she is prepared to remove dangers of defecting from the faith and is to make a sincere promise to do all in his or her power so that all offspring are baptized and brought up in the Catholic Church;
2/ the other party is to be informed at an appropriate time about the promises which the Catholic party is to make, in such a way that it is certain that he or she is truly aware of the promise and obligation of the Catholic party;
3/ both parties are to be instructed about the purposes and essential properties of marriage which neither of the contracting parties is to exclude.
I think he’ll come around eventually, but I thought I would check on it, just in case.