Magisterium vs. Murk

Mark Shea writes about "the shadow tradition" that can appear to be associated with Sacred Tradition but is hardly part of it. Association can be confusing, but that's why we need the Magisterium: a certified (in both Scripture and Tradition), tried (2000 years and still functioning well), and guaranteed (by Christ's promise and the power of the Holy Spirit) teaching authority (delegated by Christ exclusively through his Apostles and in a special way through the chair of St. Peter) that makes the Church the pillar and foundation of truth. This is not to say that what the Magisterium teaches is always obvious or always easy to give assent to. But it is a power to bind and to loose that comes from our Lord, the head of the Church, and so we must give it assent even when its pronnouncements are neither easy to grasp nor to obey. On the other hand, we are called to observe all that the Lord has commanded through the Apostolic Church. We are not called to simply pick and choose which ones we like.