I thought I made that distinction very clear.
The statements of faith, the creeds, the constitutions, the by-laws... all serve as the point at which the assembly is unified and does business.
Those things are vital to the assembly, and should on a regular basis be reviewed by all members to verify there is unity or a need for revision.
However, there is also (as I attempted to show) that practical living of the believers is served by learning the principles of the Scriptures, the Scriptures in which they will use to discern, to combat, to teach others ...