Why the obvious title? In reading S. Kent Brown's commentary on the book of Luke it struck me that CHRIST only had 12 special witnesses in the innermost circle. Why is this important? Because modern corrupted Mormonism would like its members to believe you need 15 apostles to run a church. 3 for the First Presidency and 12 for the quorum.
GOD does not change, so why would Mormons need 15 apostles? I guess to share the wealth of their priestcraft among an extra 3 people who have never seen the SAVIOR, and have apparently never read the New Testament.