"Sacred Tradition and Sacred Scripture, then, are bound closely together, and communicate one with the other. For both of them, flowing out from the same divine well-spring, come together in some fashion to form one thing, and move towards the same goal." Each of them makes present and fruitful in the Church the mystery of Christ, who promised to remain with his own "always, to the close of the age".
Source: Catechism of the Catholic Church (Vatican.va)