Jeg vet lite om katolsk tro og vil derfor gå rett til det jeg mener er kjernen i alt som har med tro å gjøre;
regner dere bibelen som eneste veiledning/rettesnor for et liv i tro?
Nei, vi gjør ikke dette, på lik linje med alle ikke-protestantiske kirkesamfunn i Østen. Det er vanlig i katolsk - og ortodoks litteratur - å regne sola scriptura, idéen om at Bibelen alene er kilde til alle dogmer, som en ny lære som reformantene sto bak. For å gi et eksempel på standard kritikk av sola scriptura fra ortodoks (og katolsk) hold:
The Orthodox have multiple objections to the doctrine of sola scriptura, on the grounds of reason, on practical grounds, and also from church history and tradition. First, sola scriptura fails its own test, since such an idea is found nowhere in the Bible. It is true that the Bible speaks very highly of the value of Scripture (e.g., 2 Tim. 3:16), but never does it say that it is exclusively authoritative, nor even that it is supremely so. Ironically, the Bible describes the Church (not itself) as the “pillar and ground of the truth” (1 Tim. 3:15).
St. Paul also commands believers in Thessalonica not merely to read the Bible, but to “stand fast and hold the traditions which you were taught, whether by word [of mouth] or our epistle” (2 Thess. 2:15). That is, Paul expects them to hold to church tradition, whether it is written (Scripture) or passed on by oral teaching. Readers of the Protestant-made New International Version (NIV) translation will miss this, because the NIV translates the Greek word paradosis (“tradition”) as “teaching” when it is used in a good light but as “tradition” when used negatively. This approach distorts what the Bible actually says. The biblical text distinguishes between two different kinds of paradosis—the tradition of man and the tradition of God.
A number of practical problems are introduced by sola scriptura, as well. The old Roman Catholic characterization of sola scriptura, “every man his own pope,” also seems apt to the Orthodox, though we see individual infallibility as the problem, no matter who claims it. Because every believer becomes an authority in interpreting the Scripture, we have to ask how we are to defend against heresy. If everyone is qualified to interpret Scripture, who can judge if someone is teaching heresy? And how can Protestants object to an infallible papacy while teaching their own personal infallibility? The pope is not infallible, but I am? (Damick, Andrew Stephen. Orthodoxy and Heterodoxy.)
Kjernen i katolsk lære er hellig tradisjon. Vi verdsetter skriften, naturligvis, men vi er dypest sett lojale til Kirken og dens lære, som gitt i bl.a. fedrene og konsilene; den hellige ånd virker fortsatt gjennom Kirken i dag. Vi argumenterer for at ikke engang hele urkirkens lære er å finne i NT. F.eks. oppmuntrer St Paul eksplisitt oss til å ta vare på tradisjonene: "Stå derfor fast, søsken, og ta vare på de overleveringene vi har undervist dere i, enten muntlig eller i brev" (2 Thess 3,15). Ordet "overleveringene" er her brukt til å oversette "paradosis", gresk for 'tradisjon'.
For mer om forholdet mellom Bibel og tradisjon se katekismen: http://www.katolsk.no/tro/kkk/k1_03.