Alright. I’ll try this one more time.
The most simple answer is that
both Tradition and Scripture make up a
single deposit of the word of God, which is entrusted to the church. This comes from the Dogmatic Constitution on Divine Revelation (section 10).
In other words, as the Second Vatican Council declared, Sacred Tradition and Sacred Scripture are
“like a mirror, in which the church, during it’s pilgrim journey here on earth, contemplates God”. This is from the Dogmatic Constitution on Divine Revelation (section 7).
More to the point, however, God’s Word of revelation comes to you through words spoken and written by human beings. Or, as the Dogmatic Constitution on Divine Revelation (section 9) states, Sacred scripture is the utterance of God put down in writing under the inspiration of the Holy Spirit. Sacred Tradition, on the other hand, is the handling of God’s Word by the successors of the apostles.
In either case, the Holy Spirit is at work. And, in all these things, the Magisterium is placed in charge. In this sense, it all comes around full circle. In other words, speaking of the infallibility of the Church, the pope, and the bishops, Vatican II says…
In other words, the Church could not suddenly declare that the doctrine of the trinity was wrong for example. She could not just suddenly claim a new revelation that contradicted the previous teaching, not had any precedent in Church history either.
But, since the Catholic faith beleives that God will keep his promises, we as Catholic do not worry about these kinds of pernicious teachings worming their way into the Church’s teachings. e are simply trusting that God will keep his promises depite our own ability to fail him.
God is not depending on us. We’re depending on God.
And the fact that the Church has indeed stood gaurd as the ‘pillar of truth’ over the last 2,000 years, protecting from false teachings, fairly well indicates that she has been doing an excellect job via the Holy Spirit to protect the deposit of revelation which came directly from God.
Does this clarify things better?