Assuming that you're sending the card to a male who has been both ordained by an organized religious body and earned a doctorate in any field of study but usually in this case, a Doctor of Divinity (DD), "Reverend Doctor _" (Rev. Dr. _) is exactly correct.
The correct way of addressing a Catholic priest is The Reverend John Smith, J.C.D. (the initials for his doctorate are OPTIONAL) on the envelope. The head of the letter would be Dear Father or Dear Father Smith, and in conversation, Father or Father Smith (if there are more than one around). You do not normally acknowledge a priest's degrees in addressing him, unless there is a reason, like in a footnote, then The Reverend John Smith, J.C.D.
When addressing a greeting card to a judge and his wife, you should address the judge first with their official title, such as "Honorable [Full Name]". Then, include "and Mrs. [Last Name]" or "and [Her Full Name]" on the same line. For example, it could read "Honorable John Smith and Mrs. Smith". It is important to show respect and proper etiquette when addressing individuals with official titles.
Executive Assistant to John Smith
If the letter/invitation is primarily to the reverend but also her husband: Rev. Mary Smith and Mr. John Smith If the letter/invitation is primarily to the husband but includes the wife: Mr. John Smith and Rev. Mary Smith If it is strictly a business letter and not church related: Mr. & Mrs. John Smith
The man's; Mr. and Mrs. John Smith, Mr. and Ms. John Smith, Mr. John Smith and Miss Jane Jones.
When you are addressing a letter to married doctors it would be: Drs. John and Jane Doe.
Mr. John M. Smith and Dr. Mary F. Smith is correct, or John M. and Mary F. Smith, or Mr. & Mrs. John M. Smith. One should never become awkward in usage for the purpose of being politically correct. It simply draws people's attention unnecessarily.
If you were sending a letter to John Smith, MD - you could address the letter to Dr. Smith.
The salutation used for the envelope address can be either Dr. John Smith and Dr. Jane Smith, or Drs. John and Jane Smith. If you are writing a letter to both doctors, then he greeting in your letter can be Dear Drs. Smith.
Can you use a prefix and suffix both after a person's name such as Mr. John Smith, CPA?
When addressing a letter to a Sir and a Lady together, you should use the format "Sir [First Name] [Last Name] and Lady [First Name] [Last Name]." For example, if addressing Sir John Smith and Lady Jane Smith, you would write: "Sir John Smith and Lady Jane Smith." In the salutation, you can start with "Dear Sir John and Lady Jane," or simply "Dear Sir and Lady Smith."
John Smith was one of them...