"The infallible rule of interpretation of Scripture is the Scripture itself; and therefore when there is a question about the true and full sense of any Scripture (which is not manifold, but one), it must be searched by other places that speak more clearly."-The Baptist Confession 1677/89, 1.9
So often modern conservative Christians approach Scripture with a view towards "number of verses". You'll hear the argument, "where does the Bible say that?!" Or, if you seek to see how Scripture is put together as united whole, you will often get the retort, "But the Bible doesn't say that." This comes into play when certain Reformed doctrines are discussed, the biggest being covenant theology. The irony is that so many cherished, and orthodox doctrines themselves are built upon how Scripture is put together, vs. one single proof text (i.e. The Trinity being the chief example).
When we approach the Scriptures, we must be willing to see how the Scriptures use the Scriptures, and specifically how the Bible is put together. Why does Jesus in Matthew 19 refer to the Decalogue with the Rich young ruler? Why does Paul refer to the Decalogue in Romans 12? Why does much of the Sermon on the mount utilize themes from the Decalogue? Why does Paul use a quotation from the Decalogue in addressing the children of Ephesus in Eph 6? The answer must be that Scripture itself puts a priority, or a weight on the Decalogue. We don't need a writer to explicitly tell us in the New Testament that the 10 Commandments are still of use for the Christian today (Third Use of the Law) because we see the Bible itself place a primacy on it. We don't need Paul to create a 17th chapter of Romans to tell us, "By the way, the 10 Commandments are still binding upon Christians today", because nowhere are we told that they are abrogated, and Scripture itself uses them as continued assumed standard. And, if they were given as a whole then, why divide them now?
My point is, our interpretation cannot be driven by proof texts alone. We must look at how Scripture is put together as a whole, and how it uses itself.