1. When your partner is leaving: 안녕히 가세요 When you are leaving : 안녕히 계세요 2. 신의 은총을 It is not common Korean expression. Even Christans in Korea don't use it in general. 3. morning: 좋은 아침입니다. evening: 좋은 저녁입니다. But, above are not common Expressions. Usually people say "안녕하세요" regardless of time.