A conservative Christian told me he was invited to sign the card for a newly married gay couple in his office. He avoided doing so because he doesn’t believe in gay marriage. I suggested just signing “Best wishes!” because Christians are called to wish the best to everyone. He was worried that this would be interpreted as approval of the marriage. I countered that not signing could be misinterpreted as his being a dour religious bigot. Either way, misunderstanding could result. While it isn’t an easy question, I think a simple blessing is best.