There is a great scene in "The Lord of the Rings," where Galadriel gives Frodo the light of Eärendil, and blesses him with it so that it may be "a light for you in dark places, when all other lights go out." This light actually saves his life. Even when he no longer holds it, a friend (i.e., Sam) comes and shines it and delivers him from death with it. I've always wondered if Tolkien took this from the Bible, as it says many similar things about itself in terms of being a lamp to our feet and a light in dark places.
The surest path to a forsaken faith (either partially or en toto), or to have your light go out, however, is to believe that the Bible contradicts itself, which is really a transfer of belief from thinking that the Bible is primarily a divine document to a primarily human one. The more human we make the Bible, it seems, the more we feel comfortable dismissing it, or at the very least, diminishing its authority in our lives. But Christianity, and the Bible itself, has never pretended to be anything other than a Divinely inspired book of humans, or a humanly written book of God. When God actually speaks through humans, there is no reason to pretend that it fell out of heaven on golden plates or was written by angels or by men who were seized and merely wrote in a mechanical fashion via dictated words that expressed nothing of themselves in the text. In other words, when you're a document that actually is the Word of God, you don't need to make yourself pretty enough to fool the masses. You have power in and of yourself, and complete confidence and security that you will accomplish exactly what God desires you to accomplish.
This is important to note when we discuss whether the Bible contradicts itself, because in all actuality, it only does so if one believes that it does. In the same way, these variations are complementary only if one believes they are as well. I'm speaking, of course, in the ultimate sense, when the entire canon is considered. Either the variations and diversity complements and clarifies or it contradicts itself. Of course, even contradiction can be used as complementation and clarification, but in the ultimate sense, both take faith as their presupposition.
And that is the point. Both take faith. Neither one can grasp the reality of the text without it. One must disbelieve that the Bible is divinely inspired in everything it teaches, and hence, believe (i.e., have blind faith) that the Bible is a solely or primarily a human document in order to see ultimate contradiction. Likewise, one must believe that it is divinely inspired in all that it teaches and thus believe that it never contradicts itself in the ultimate sense, since God never contradicts Himself and is One in order to see clarification and complementation.
But the question becomes, Why would God fill the Scripture with so much variation that so many unbelievers can just see it as contradiction? Doesn't God want everyone to believe?
Well the short answer to that is, No, He doesn't. That's clear in Scripture. Which leads me to the long answer: The Bible is set up much like the parables are in Jesus' ministry. It functions as a message for the unbelieving who read it to see but not see, to hear but not hear. But let's back up, as you may have not been aware that the parables in Jesus' ministry were meant to hide the truth from the unbelieving, not necessarily in a way that they would not always be able to get what the parable was saying, but in a way of expressing God's rejection of anyone who would approach Him in arrogant self-trust and unbelief.
So let's look at the very reason Christ gives parables to the people, as many believe that parables were meant to clarify truth and help the masses understand God's truths through stories. Christ does use them as such in a way, but only because He clarifies the teachings of the stories with direct propositions that explain them. These explanations, however, are only given to the disciples. To the unbelieving masses, who approach in unbelief and distrust, the parables function only as a condemnation of their unbelief:
And the disciples came and said to Him, "Why do You speak to them in parables ?" And He answered and said to them, "To you it has been granted to know the mysteries of the kingdom of heaven, but to them it has not been granted. "For whoever has, to him shall [more] be given, and he shall have an abundance; but whoever does not have, even what he has shall be taken away from him. "Therefore I speak to them in parables ; because while seeing they do not see, and while hearing they do not hear, nor do they understand. "And in their case the prophecy of Isaiah is being fulfilled, which says, 'You will keep on hearing, but will not understand; And you will keep on seeing, but will not perceive; For the heart of this people has become dull, And with their ears they scarcely hear, And they have closed their eyes Lest they should see with their eyes, And hear with their ears, And understand with their heart and return, And I should heal them.' "But blessed are your eyes, because they see; and your ears, because they hear. (Matt 13:10-16)
All of the gospels, including John, which is not a Synoptic, repeats this in one way or another. The parables are meant to confuse the unbelieving about the truth. They are not meant to clarify and explain truth to them. God does not give truth to those who do not believe. He causes them to be deceived further. He causes them to be utterly convinced of what is false (2 Thes 2:11-12).
Hence, "he who has an ear to hear, let him hear" is a continual phrase that Christ repeats because what He says concerning God is only for those who have been given an ear to hear, i.e., those who believe. Notice, in the Matthew passage that the disciples, who believe, are said to be blessed because they are allowed to get it. The parables, for them, are clarified and explained by direct propositional statements, not by stories. (As an aside, I find it interesting that the pomo church is so interested in stories, rather than propositions, when the stories without propositions are meant only to confuse the masses.)
Even the signs Christ performed could not open the eyes that God had shut because of their unbelief (John 12:37-43). So it is clear that God Himself does not want to teach truth to everyone. He does not want everyone to "get it." But instead, He only seeks to communicate clearly to those who completely believe, those who trust in Him above themselves.
I would say the same thing for the entire Bible. I think that the Scripture is set up this way, so that there are things in it that cause those who would not completely give themselves over to God to stumble and fall. I think it is written in such a way, through humans, as to be convincing to those who disbelieve to be solely or primarily just a human document, but also written in such a way so as to be primarily a divine document written through humans to those who believe. In other words, it is both a faith builder and a faith destroyer all in itself, depending upon how one approaches it. If approached in faith, it builds and brings one closer to the truth. If approached in disbelief, it destroys and removes one further from it. The man who believes receives all, and the man who doubts (in a way that places faith in himself over God) receives nothing.
So what is the answer to the question, Does the Bible contradict itself? The answer is, It depends upon who you are, and with what faith or lack thereof you approach it. As James says, "Let not that man [i.e., the man who doubts and does not approach God in trust] expect that he will receive anything from the Lord" (1:7).
For those who believe, however, the Bible's variations function as clarifications and complementations of the other truths that are set beside them. In this way, these clarifications bring us into further truth, because they help us understand other truths more clearly. For those who disbelieve, these are contradictions that confuse and fog up the unbelievers grasp of truth, but for those who believe, they clear up the skies and allow us to see the Son all the more.
For me, the Bible never contradicts itself in what it teaches. It is "a lamp shining in a dark place, until the day dawns and the morning star arises in your hearts" (2 Pet 1:19). As for me, it has always been a brightly shining light in a very dark, dark world; but that's because the Lord has granted belief to me. Without His mercy upon me, I would be lost in confusion and darkness, and the Bible would be a host of human contradiction, making no sense to me. My hope for you is to have the same mercy from God that would grant you belief. So pick up your Bible and believe, so that it may be "a light for you in dark places when all other lights go out."