Question: Can Catholics attend a wedding between two nonpracticing Catholics who are being married in a restaurant or a destination venue? Would this be a “serious sin” to attend such a wedding?
Answer: Thank you for your question.
“The Church does not explicitly forbid Catholics from attending presumptively invalid marriages. Catholics must use their own prudential judgment in making the decision, keeping in mind the necessity to uphold the Catholic understanding of the sanctity of marriage.
“To make such a judgment, you might ask yourself if you believe the couple is doing the best that they can to act honorably and according to the truth that they have.
“For example, you might decide to attend the presumptively invalid wedding of a couple who is expecting a child (thereby attempting to provide a family for that child); but you might decline to attend the presumptively invalid wedding of a couple you know to have engaged in adultery (thereby destroying previous marriages and families).
“While there may be just reason to attend a particular wedding that will be presumptively invalid, it cannot be recommended to participate as a member of the wedding party in such weddings. There is a difference between attending as a nonparticipating guest and actively involving yourself in the wedding.
“If you are not attending the wedding as a matter of principle, then it cannot be recommended to attend a reception or give a gift to honor an occasion that you believe in conscience that you cannot celebrate.
“It can be recommended to write the couple a letter in which you express your love and prayers for them. (If prudence suggests it, it is fine to withhold from them what you will be praying to God that they obtain, such as the grace of repentance and conversion.)
“In the case of same-sex partners, the Church has spoken so strongly against ‘same-sex marriage’ that it cannot be recommended to attend or celebrate ‘same-sex weddings’ under any circumstances.”