You can still accept Jesus Christ as your Lord and Savior, while accepting all of the wonderful things that modern science has taught us about our Universe.
I know there are many Christians out there who believe in Biblical inerrancy— that it is the literal word of God, and that each and every word must be literally true. What I want to convince you is that you can take a broader view without losing what is essential about being Christian. You need not abandon your faith in order to accept Evolution or the Big Bang, but you will need to think about it in certain ways.
The wonder and beauty of our Universe is amazing. And, by this, I'm not just referring to the tremendously beautiful images we've seen come out of astronomy. Rather, I'm referring to the beauty that is inherent in what all fields of science have discovered. The fact that we can understand how natural processes work, that we can make predictions about them and learn about things that happened millions of years ago, is astonishing. Science is a creative human endeavor, the greatest works of which are on par with Beethoven's 9th symphony. Indeed, that there are harmonies intrinsically pleasing in music is in fact the result of one of the observations of science— that mathematics is the language that seems to describe the mechanisms of the natural world. Musical pitches come in resonances as a result of the mathematics of wave mechanics. Similarly, the fundamental things about our world that we know to be true are beautiful when understood. That protons, neutrons, and electrons can combine together in ways not just to produce the fascinating and complicated things that we call atoms, but can on larger scales produce elephants and trees and waterfalls, is mind-boggling. What's even more amazing is that we can understand how all of this works through science, and through science we can come to more deeply appreciate the beauty of our Universe.
There are some things science has taught us that make clear that all of the Bible cannot be read as literal history. Humans as a species evolved from earlier species, as did all other species present on Earth today. The Universe is billions of years old, several times older than the 4.5 billion years that is the age of our Solar System. Evolution and the Big Bang are two of the main things that creationists object to. Yet, they are lynch pins of their scientific fields, biology and astronomy respectively, without which much of the rest of the field doesn't make sense. Everyday experience— be it modern medicine, or the unmanned spacecraft we've sent through the Solar System— indicates that these fields are on to something, for we've been able to use them to great effect. It just doesn't make sense to throw out these lynchpins, and then, by necessity, much of the rest of those fields.
However, just because the Bible cannot all be literally true does not mean that it cannot be true. Before the wedding of a good friend of mine, the Episcopal minister told a parable about Biblical literalism. He said that, suppose after they've been married a few years, Mike gets home from work before Margo, and is tremendously moved watching a very beautiful sunset. When Margo comes home, Mike wants to convey this to her. Does he say, "because cross-section for scattering of light is higher at shorter wavelengths, a greater fraction of longer wavelength light was transmitted through the atmosphere, allowing a preferentially red hue to reach the clouds overhead"? No... that doesn't really convey how he was moved by the sunset. Rather he says, "The sky was on fire!" Does he literally mean that there was a runaway exothermic process of Oxygen combining with other molecules in the sky above? No! And, yet, the latter statement better conveys what he is really trying to say than does the factually true statement.
Jesus himself taught in parables. Humans frequently learn and pass on understanding through stories, and we frequently are able to internalize and relate to lessons when they are taught in the form of stories. As such, there is truth in many of the Bible stories that we know from modern science cannot be literally true. If you think about it, the Bible becomes more interesting, and indeed worthy of greater thought, if you realize that the divinely inspired Word of God need not be a mere dictation of historical events, but rather are stories that we are meant to think about and learn from, and to bring new things to as we come to understand more about our Universe.
You can find some prominent science bloggers who will assert that it is not consistent both to fully accept modern science, and to hold religious faith. They are wrong. Science addresses the mechanisms of the natural world. It is true that in the past, when we didn't understand the natural world as we do today, we used religion to explain how some things happened. Today, however, science has proven to be the process whereby we can understand how the world works. But science does not provide meaning. This is why I am asking you, if you are a creationist, to please consider that your faith can remain an important part of your life, even if you cast away the need to deny things that humanity knows to be true as a result of the efforts of modern science.
Did God create the Universe in seven 24-hour days? No. Did God create humans in their current form from nothing? No. But neither of these need reduce in any way the role of God the Creator, once we understand that God is ineffable, that God is something that works and exists in a way that humans cannot fully understand. It appears that we can fully understand the workings of nature. We don't, but every year we know more. Personally, I think it greatly reduces the role of God as Creator to say that his role was simply to will things into existence. That's such a mechanistic feat. To consider that to be what is meant by God's Creation undermines the mystery of God. It makes God no more than a video game programmer, who wills into existence the worlds of games by tapping away on a computer keyboard for a while, and then lets them go on their way.
I have to admit that I don't fully understand myself what I believe to be God's role as Creator— but then again, why should humans expect to fully understand any aspect of God? God's Creation is something that is ongoing. It's not God reaching in and pushing things about here and there, making things happen like a software programmer debugging his code. Rather, God's Will is a desire for the Universe, a way that would seek to have things become better. Science has given us a view of the Universe that experimentally works, and that view does not include a supernatural entity coming in and deliberately making conscious and directed changes. On the other hand, it's very clear that there are natural conscious entities making changes all the time— us. And, when those changes are for the better, might they not, at least sometimes, be divinely inspired— whatever that really means? To me, the miracle of God's Creation is both just the possibility and potential inherent in the Universe that may come to pass as a result of natural means, and the actions of conscious beings when they seek to make the world a better and more beautiful place. Whether God is the "condition of possibility of any entity whatsoever" (to quote Terry Eagleton), or whether it is an integral property of conscious thinking beings, I don't know, but I do know that God is more than a dude with a flowing white beard who makes stuff sometimes.
In summary, the Universe is an amazing and inspiring place. There is so much elegant beauty in the scientific truths known as Evolution and the Big Bang. There is so much wonder in our world and in our Universe, that it is sad to reject those on the basis of a particular reading of the Bible. You can fully accept God the Father and Jesus the Savior without having to reject these things humans have come to learn about the natural world. I'm asking you to take a broader view of Christianity, to be able to understand the Bible as holding truths that need not always be simplistic literal accounting of events. To seek to further understand the Universe is a wonderful calling. It is not necessary then to hide the light of that understanding under a bushel when it requires us to think more deeply about our faith!
(Afterward: I'm going to be fairly strict moderating the comment thread of this post. I do not want atheists who feel the need to denigrate religion commenting here; this post is not for you. The goal of this post is not to argue in the debate about whether or not it's OK to be both religious and scientific; I personally consider that issue settled, but will continue to address it in other posts. Rather, the target audience of this post is the religious, and in particular creationists, in an attempt in a small way to show how I see Christianity being able to accept the modern scientific world-view.)