Are you arranging a wedding in a church? Or perhaps a christening, a golden wedding or some such service? And you have chosen some hymns to sing?
Then I have some good news and some bad news for you. First the bad. The songs will fall flat, just embarrassingly awful; most people can't sing, don't want to sing, don't know the hymns, come from another church or planet, just awful.
Good tip: Hire the church choir! They can sing. They know the terrible organ and acoustics in the church. Maybe some of the congregation will join in.
Save the day! Hire the choir!