170 We do not believe in formulae, but in those realities they express, which faith allows us to touch. "The believer's act [of faith] does not terminate in the propositions, but in the realities [which they express]."56 All the same, we do approach these realities with the help of formulations of the faith which permit us to express the faith and to hand it on, to celebrate it in community, to assimilate and live on it more and more.

171 The Church, "the pillar and bulwark of the truth", faithfully guards "the faith which was once for all delivered to the saints". She guards the memory of Christ's words; it is she who from generation to generation hands on the apostles' confession of faith.57 As a mother who teaches her children to speak and so to understand and communicate, the Church our Mother teaches us the language of faith in order to introduce us to the understanding and the life of faith.