The thought of the cart before the horse hits me here, although in a sense it might be the other way around, but there are those who think the faith is at stake unless one holds to their reading of Genesis. That if you deviate from that you are actually undermining the faith once for all delivered to the saints.
There is no doubt that the Bible is not only important, but in a true sense foundational to faith. That is where we go to find the good news on which our faith is to be grounded. But there is more albeit from that as a starting point. The Bible itself holds out tradition as one means of preserving the faith. We can see that in the description given to the church, called no less than “the pillar and foundation of the truth.” We need to consider that more, rather than retreating back to a sola scriptura position. Scripture is unique no doubt, no less than the written word of God . It comes first so that I hold to primera scriptura. It actually is (like most everything) more complicated than that because we go to scripture first, we go elsewhere, than we return to scripture. All has to be judged by scripture, including tradition. We can say “primera” means first in all things and in doing so, I suppose we’re not far removed from a sola scriptura position. Even though in its right place, tradition is the place where God’s written word can and perhaps we should say is to take root and flourish.
The faith is dependent on scripture along with tradition in its right place. But the heart of faith is the gospel. Jesus Christ front and center, his cross in both his death for sins and resurrection for new life. His ascension and promise of return. That is the good news in Jesus. That is where our faith must be rooted. Anything less than that is not saving faith.
Is our understanding of Genesis important? You bet. I hold to an evolutionary understanding of origins, what might be called theisitic evolution or evolutionary creation. With such an understanding, I read Genesis differently than those who hold to a creation science view. We all want to read scripture faithfully. We all want to be true to the text of scripture. And the most important reason why is that we want to be faithful to the gospel. In fact our very faith and life depend on that gospel. In the end our faith does not hinge on how we read Genesis. But this is where it gets tricky. People have lost their faith by supposing that Genesis stands or falls on a certain scientific understanding, when Genesis itself is not about a scientific understanding, even while it incorporates some old science (a solid sky, like a material dome). Genesis is about God making and setting the table so to speak of a temple in which he dwells in terms of creation and ultimately new creation in and through Christ (see John H. Walton, The Lost World of Genesis One: Ancient Cosmology and the Origins Debate).
Responsible readings of Genesis will seek to be true to the text and to the good news of God’s grace and kingdom come in Jesus. In keeping with all of scripture. In the end our faith depends on that gospel. Nothing more and nothing less.