A couple may have a difficult time locating a minister for their wedding if they are not members of a church congregation.
I work with a couple to plan a ceremony that is expressive of their beliefs. The bride and groom have planned every detail of their wedding event and I believe they should have the same opportunity regarding the ceremony itself. I officiate at the type of ceremony desired by the couple whether it's a civil or religious ceremony - whether it's denomination specific, non-denominational, inter-denominational or inter-faith.