Although it is possible that all these people know that “good” derives from an Old English word for “God” and refrain from saying “Good morning” or “Good night” to you out of fear that Muslims would be offended by a casual reference to God, it is more likely that they simply do not know what would be appropriate. Although, I must say that you have given them a clue that you will not be offended by offering these greetings to them. Assuming that you know that “Good morning” or “Good night” is wishing you a godly morning or a godly night, and such a greeting is not opposed to your beliefs, the next time your greeting is not returned you might pause a beat and then say gently, “It’s okay to wish me a ‘good morning,’ too. I would appreciate the courtesy.”