The word credo means “I believe.” A creed is therefore simply an expression of belief. The statement, “I don’t believe in creeds” is therefore nonsense because not “believing in creeds” is a belief; it is a creed. Therefore, the only question is whether what an individual or a community confesses in their creed is true or not. It is the proper application of the Apostolic Rule of Faith according to the One-Source View that makes any creed or judgment of any expression of the Church authoritatively true. The Two-Source View in the form of “Solo” Scriptura or Qualified Infallibility does not generate authoritatively true creeds.
Also see Apostolic Rule of Faith, Certain Knowledge, One-Source View, and Sola Scriptura.