Confessions and creeds are just merely ways in which we can agree on what we believe (much like a statement of beliefs) and can be used to teach this theology to everyone.
Take a look at this article from January's Tabletalk Magazine from Ligonier Ministries written by Dr. Douglas Kelly:
"Out of this crucible of controversy came several confessions that, with general brevity and clarity, express the main thrust of the teachings of Holy Scripture on salvation and holy living. Because of their biblical teaching, they have the value of guiding us as much today as they did our forefathers centuries ago. It is a mercy for the church today not to have to reinvent the wheel. Through the creeds and confessions, we abide in the health and safety of “the communion of the saints.”