When I was in seminary 50 years ago, the principle was set in this sequence as in the title: the primary is the faith and the liturgy follows the principles of the faith. It was considered modernist view, that the faith developed from the common prayers, and consequently e.g. the Gospel were written based on the oral tradition, which based on the prayers, liturgy.
The view, that the principal is the faith and the liturgy is secondary was argued by the fact that the original Christian prayer was psalm based (something from the secure level of the Old Testament) the originally gnostic based hymns with theological meaning were considered suspicious after the the time of St Ambrose and St Leo the Great, after the time when the faith was already clearly established by the Ecumenical councils.
Who, when and why changed the sequence, and made the prayer primary before the faith?