In the "Creed of Athanasius" does "before all things" mean "sooner" or "most important"?

Please see this question for why I think the Creed claims to be the declaration of the catholic church rather than merely clarifying the catholic position regarding the doctrine of "Trinity": The creed starts out like this: > Quicumque vult salvus esse, **ante omnia opus est**, ut teneat catholicam > fidem: Quam nisi quisque integram inviolatamque servaverit, absque > dubio in aeternum peribit. Fides autem catholica haec est: ut unum > Deum in Trinitate, et Trinitatem in unitate veneremur. Neque > confundentes personas, neque substantiam separantes.... > > Whosoever will be saved, **before all things** it is necessary that he > hold the catholic faith. Which faith except every one do keep whole > and undefiled; without doubt he shall perish everlastingly. And the > catholic faith is this: That we worship one God in Trinity, and > Trinity in Unity; Neither confounding the Persons; nor dividing the > Essence... Athanasian Creed on Wikipedia Is the creed saying that the Trinity dogma should be the **first** thing that one is taught? Or that believing this creed in its entirety is **more important** than any other matter of faith than anything else? In particular are we to understand the creed as saying that "This is the body of truth of the catholic church and it is upon the belief and embrace of the contents of this creed that determine whether or not you will be saved."