It does support the preaching of the Word. No one denies the word was, and still is spread by preaching. It is also spread by reading.
In fact, those who embrace the theory of sola scriptura attempt to use the Bible to contradict, to prove baseless, certain Church teachings, such as the Real Presence and the existence of purgatory.
We have asked numerous times on this board for catholics to give us clear writings where the apostles passed on teachings on the assumption of Mary, her immaculate conception, purgatory, indulgences, the papacy, the office of cardinal, archbishop, etc.
To date none have been able to.
Your comment: To date none have been able to.
I disagree. There has been many postings about those subjects.
Do your homework and I am sure that you can find detailed information if you are seeking the Truth.
Salvation has many links that will help you understand the teachings of the Catholic Church, along with many other Catholic links.
http://www.freerepublic.com/~salvation/