Why does the faith require definitions and formulas?
Faith is not about empty words but about reality. In the Church, condensed formulas of faith developed over the course of time; with their help we can contemplate, express, learn, hand on, celebrate, and live out this reality.
Without fixed forms, the content of the faith would dissipate. That is why the Church attaches great importance to definite sentences, the precise wording of which was usually achieved painstakingly, so as to protect the message of Christ from misunderstandings and falsifications. Furthermore, creeds are important when the Church’s faith has to be translated into different cultures while being preserved in its essentials, because a common faith is the foundation for the Church’s unity.
CCC section (170-184)