Here is a favorite verse quoted by Catholics to support Church Tradition, which by definition, are doctrines not to be found within the covers of any Bible-
John 21:25 And there are also many other things which Jesus did, the which, if they should be written every one, I suppose that even the world itself could not contain the books that should be written. Amen.
Well, there it is. Absolute indisputable proof that not all doctrines Jesus taught are included in scripture! Imagine all the teaching Jesus might have done that simply was not included in the Bible. Who can tell, maybe we are supposed to pray to Mary and Saints. Maybe Mary is the Immaculate Virgin and Queen of Heaven. Who could deny that these and other doctrines of Tradition might just be true, but are part of the unrecorded doctrines this verse speaks of?
If you encounter this kind of Catholic logic then direct them to the following verses-
John 20:30 And many other signs truly did Jesus in the presence of his disciples, which are not written in this book:
John 20:31 But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name.
Well this puts a different light on the same subject doesn't it! Here John, the very same author, is saying that the Bible contains everything you need to come to a saving faith. Clearly John is saying that by believing in Jesus Christ (faith) you are saved (have life). John has seen to it that a sufficient number of Jesus' miracles are recorded that you can come to believe in Him and be saved. John speaks of some of what Jesus did as being unrecorded, signs, miracles, etc., but does not even hint at unrecorded doctrines essential for salvation, in fact he adequately refutes such a notion.
So, rather that having a hole (21:25) big enough to drive a truck through (filled with unbiblical doctrines), the book of John completely closes off any attempt to introduce spurious doctrines under the guise of Tradition (20:30-31). Not even a church mouse can get through!
Curious thing about the Catholic Doctrines of Mary, some of them have been declared by the church to be articles of faith. That is to say that you can not be saved if you fail to accept them (at least if you claim to be Catholic). Isn't this in direct opposition to what John is saying in chapter 20:30-31? Indeed it is! According to John, everything needed for a saving faith IS written down in scripture!
A Catholic rebuttal by Mario Derksen.
Go to The Sola Scriptura Principle - Does the Bible Teach it?