Obviously, on any theological journey, Scripture must play a major part in shaping and defining our understanding of Truth. (By the way, I believe theology is foundational as what we think about God affects everything about us; and the task of theology must inevitably be seen in pilgrimage terms as our understanding should be developing and 'always reforming', never static and rigid).
So Scripture is vitally important but the centrality of Christ is really relevant here as well. If we do not read the Bible through the lens of Christ then we will totally misunderstand it. For instance, I think if we try to base our view of God by reading the Old Testament without this lens on, then we end up with a very different God than the one who is revealed in Christ. The Pharisees and teachers of the law made this mistake all the time. They studied their Bible diligently but they so missed the fact that it was all about Jesus (John 5:39-40) that they plotted to have the author of life killed. They missed the Word of God in the very words of God.
I think perhaps many Bible-believing Christians are building their lives and faith on what they think is the foundation of the word of God, but they have ended up with a warped understanding of Scripture and God. Hebrews 1:1-3 tells us that, through the OT prophets, God revealed something of himself 'at many times and in many ways', but that now 'he has spoken to us by his Son' and that that Son is the final and full revelation of God - 'the radiance of the Father's glory'. Christ is the only foundation we can build on (1 Cor.3:11), and so the written Word must be understood through the incarnate, living Word.
Here's a rough rule of thumb to help you. If your interpretation of any part of Scripture leaves you with an understanding of God that looks different than the one revealed by Christ on the cross - loving his enemies, giving himself in astounding, unconditional, sacrificial love, reconciling the world to himself, amazing us with outrageous grace - then guess what? Your interpretation is wrong. As Bill Johnson says, 'Jesus Christ is perfect theology.'
A little more on this tomorrow hopefully.