In the early days of the Church, the initial focus was on two "simple" things - the Book of Mormon and the calling of a new prophet. The earliest missionaries didn't "teach about" the Book of Mormon much; they gave someone a copy and asked them to read it. They didn't give them selected passages to teach specific doctrines; they had them read it cover to cover, while praying about it as they read.
If I could change one thing about our missionary "program", it would be to encourage our members to invite people to attend church with them and read the Book of Mormon cover to cover - only introducing them to full-time missionaries after they had expressed interest in learning more.
As I read "Preach My Gospel", the central message I get is that there are certain things that need to be accepted prior to baptism, but understanding and believing in God's grace and mercy and turning to Him with a sincere heart and open mind is what converts - not being "taught the discussions".