What part of separation of church and state are you failing to grasp. Clergy are not pharmacists, Churches are not drug stores. The former are non-secular the latter are secular. What laws apply to pharmacies do not apply to churches. A cleric is required by his church to serve his flock, not to provide services to any other people, just his people. A cleric is ordained by his church, the government gets no say in what training, continuing education or even morality the cleric must have (see Catholic church and pedophilia as an example), A pharmacist is licensed by the state with a specific set of regulations on training, morality, and ongoing education. Can you see the difference? The only organization that could force a cleric to officiate a same sex marriage is the hierarchy of that church if they decree that it is requirement for their clergy.