Sola Scriptura

Who said that the Bible alone is sufficient?

Jesus said so and Satan agreed.

But he answered and said, It is written, Man shall not live by bread alone, but by every word that proceedeth out of the mouth of God. (Matthew 4:4 KJV)
Jesus said unto him, It is written again, Thou shalt not tempt the Lord thy God. (Matthew 4:7 KJV)
Then saith Jesus unto him, Get thee hence, Satan: for it is written, Thou shalt worship the Lord thy God, and him only shalt thou serve. (Matthew 4:10 KJV)

Jesus quoted the scriptures three times, "It is written, It is written, it is written" and Satan accept that as the final proof. What is good enough for Jesus to defeat Satan is good enough for us to defeat any opponent. The Bible is the only offensive weapon in a Christian's hand.

And take the helmet of salvation, and the sword of the Spirit, which is the word of God: (Ephesians 6:17 KJV)

Unlike Jesus and Satan, the Roman Catholic Church said that the Bible is not enough. It had to be supplemented by the Traditions, which was the oral transmission of the Gospel. Why is the Traditions "oral"? It does not mean that it is not written. The "oral" Traditions were written down. It means that more Traditions can be added orally by the Pope speaking "ex cathedra". The Bible is closed, but the Traditions are not.