Heidelberg Catechism Lord's Day 29 - Questions 78-79 - Lord's Day 30 - Questions 80-81. --1. What is it- A Means to be Real Partakers of the True Body of Christ -2. How Does it Need to be Used- With Faith in the One Sacrifice for Sin Forever-3. For Who is it- For Them Knowing Sorrow, Faith, and Holiness