My friend is Catholic, and she is marrying a man who is not. She has the idea that the Church will shun her marriage, and that she can never take communion again if she goes through with the marriage. My understanding is that the Church recognizes two sacraments in other Christian faiths: baptism and marriage. Her feelings are hurt and she wants to leave the church because of this. Is her marriage valid? Or is she living in sin?
Depending on whether your friend’s groom has been baptized, the Church calls this situation either “mixed marriage” or “disparity of cult”. Either way, there are certain requirements that must be met for the marriage to be valid. For more information on this see these related posts:
How do couples of mixed faith approach marriage and raising children?Can a Catholic marry a Non-Christian?
If your friend chooses to enter into and remain in an invalid marriage then she will not be admitted to communion as long as the situation continues. See these posts:
Should a Catholic who doesn’t adhere to Church teaching abstain from the Eucharist?
Is there any way for someone in an invalid marriage to receive communion?