Before I answer this question, I want us to remember that in everything we do or in everything we strive to answer, we are to remain humble. I also want to stress that there is a danger in reading something into Scripture that is not there and that God gave us the natural world so that we might steward it well. That means learning from it, but also being honest about what we see and do not see.
Since everything we do should be Biblically based, I want to observe the creation account with you:
In the beginning God created the heavens and the earth. Now the earth was formless and empty, darkness covered the surface of the watery depths, and the Spirit of God was hovering over the surface of the waters. Then God said, “Let there be light,” and there was light. God saw that the light was good, and God separated the light from the darkness. God called the light “day,” and He called the darkness “night.” Evening came and then morning: the first day. Then God said, “Let there be an expanse between the waters, separating water from water.” So God made the expanse and separated the water under the expanse from the water above the expanse. And it was so. God called the expanse “sky.” Evening came and then morning: the second day. Then God said, “Let the water under the sky be gathered into one place, and let the dry land appear.” And it was so. God called the dry land “earth,” and He called the gathering of the water “seas.” And God saw that it was good. Then God said, “Let the earth produce vegetation: seed-bearing plants and fruit trees on the earth bearing fruit with seed in it according to their kinds.” And it was so. The earth produced vegetation: seed-bearing plants according to their kinds and trees bearing fruit with seed in it according to their kinds. And God saw that it was good. Evening came and then morning: the third day. Then God said, “Let there be lights in the expanse of the sky to separate the day from the night. They will serve as signs for festivals and for days and years. They will be lights in the expanse of the sky to provide light on the earth.” And it was so. God made the two great lights—the greater light to have dominion over the day and the lesser light to have dominion over the night—as well as the stars. God placed them in the expanse of the sky to provide light on the earth, to dominate the day and the night, and to separate light from darkness. And God saw that it was good. Evening came and then morning: the fourth day. Then God said, “Let the water swarm with living creatures, and let birds fly above the earth across the expanse of the sky.” So God created the large sea-creatures and every living creature that moves and swarms in the water, according to their kinds. He also created every winged bird according to its kind. And God saw that it was good. So God blessed them, “Be fruitful, multiply, and fill the waters of the seas, and let the birds multiply on the earth.” Evening came and then morning: the fifth day. Then God said, “Let the earth produce living creatures according to their kinds: livestock, creatures that crawl, and the wildlife of the earth according to their kinds.” And it was so. So God made the wildlife of the earth according to their kinds, the livestock according to their kinds, and creatures that crawl on the ground according to their kinds. And God saw that it was good. Then God said, “Let Us make man in Our image, according to Our likeness. They will rule the fish of the sea, the birds of the sky, the livestock, all the earth, and the creatures that crawl on the earth.” So God created man in His own image; He created him in the image of God; He created them male and female. God blessed them, and God said to them, “Be fruitful, multiply, fill the earth, and subdue it. Rule the fish of the sea, the birds of the sky, and every creature that crawls on the earth.” God also said, “Look, I have given you every seed-bearing plant on the surface of the entire earth and every tree whose fruit contains seed. This food will be for you, for all the wildlife of the earth, for every bird of the sky, and for every creature that crawls on the earth—everything having the breath of life in it. I have given every green plant for food.” And it was so. God saw all that He had made, and it was very good. Evening came and then morning: the sixth day. So the heavens and the earth and everything in them were completed. By the seventh day God completed His work that He had done, and He rested on the seventh day from all His work that He had done. God blessed the seventh day and declared it holy, for on it He rested from His work of creation.
Here is my position. I am not convinced of Darwinian evolution as the process by which God chose to create life. In Scripture, we are not given the mode of creation, only that God spoke His creation into existence and that He is intimately involved in His creation. Whether or not God used a certain type of evolution in His creation, the story is not changed and there are many evolutionists who are also good Christians and very faithful to Christ and to the authority of Scripture.
If someone believes that we are the result of some evolutionary processes, then he or she is going to interpret the creation account differently (using an organization or an allegorical view of the text); but I am under the conviction that a literal interpretation is the best interpretation of the creation account. In any manner of interpretation, the authority of Scripture is still important and we still answer the question the text was written to answer: and that is “Why?”
How do we know if evolution is true or not? Well, I don’t think it’s something we can know specifically. We can make guesses, but Scripture does not give us a mode of creation and the scientific method is incapable or proving an evolutionary process. This being said, I think it is dangerous to teach Darwinian evolution as fact because science is incapable of proving it and Scripture has not described it. The most we can say is that mutations sometimes occur and that creatures of the past have similarities with creatures on the earth today. Even DNA looks similar; but it is dangerous for us to assume that correlation means causation.
In short, we cannot know the mode God used to bring about life; only that He spoke it into existence and created people in His own image. Belief in evolution does not prohibit someone from believing in Christ.