Q&A for How to Address a Formal Letter

Address the pastor as "Rev. Smith," as the title is "Reverend." (If the pastor has a doctorate, s/he may prefer to be addressed as "Dr. Smith.")

Yes, it goes at the beginning of the letter: [First Name & Last Name], [Street Address] and [City, State, Zip Code].

"Sincerely" immediately precedes the signature at the end of the letter.

It probably doesn't matter. Use the address at which you would prefer to receive a reply.