Christianity Explained is a great short course which takes you through the basics of what Christians believe and who they are. The course, developed by Michael Bennett, has been widely used in Australia and internationally for several decades. Each of the six sessions takes about 45mins to an hour to complete, depending on how many questions your person wants to ask and discuss. It is based on the gospel of Mark, which course participants read at home in small segments for the duration of the course. It is a great tool for clearly and fully explaining the Gospel – one to one, or in a group setting. The 6 sessions focus on the meaning of:
1. Jesus, Son of God
2. The Cross
3. The Resurrection
4. Salvation by Grace
5. Repent
6. Believe

Check out the course here at The Good Book (US) or Koorong Books (Australia).