Recently I read with great dismay of a teacher who had to resign because she could not teach evolution by natural selection in a school due to the creationist sentiments her colleagues expressed.
I find this tragic and unacceptable. Our children are being deprived of education because certain people believe that their interpretation of a religious text is superior to the findings of science.
As a Christian who used to be a young-earth creationist and who has looked into this "creationism-vs-evolution" issue, I can testify that evolution is well-supported and has vast amounts of evidence to back it up - genetics and fossils. There is no controversy regarding evolution in the biological sciences; it is established fact.
The creationism-evolution "controversy" is one that exists only in the minds of those who who are not aware of how well-established evolutionary theory is in science.
Regarding the claim that evolution is "only a theory", this is correct. A scientific theory is a set of principles that explain and predict phenomena, and is higher in level of importance than scientific laws. The everyday connotation of "theory" is closer to what would be called a hypothesis in science.
Evolution is more than a hypothesis - it has been observed and its effects can be measured. For examples of evolution being observed, look up nylon-eating bacteria, ring species, the London Underground Mosquito and species radiation in island fauna.
Macro-evolution (at or beyond the species level) has been observed, as seen with the aforementioned London Underground Mosquito, which cannot produce viable offspring with its parent species.
Most mainline Christian denominations (Catholic, Orthodox and Protestant) accept evolution as fact. See the Clergy Letter Project.
As a Christian, for me science is the means by which we explore and gain knowledge of how and why God's creation works. It is a wonderful thing to explore the deep workings of the beautiful universe that God has crafted.
Yet it saddens me that there are people who believe that what we discover from science is nothing more than the deceits of the devil. This is a insult to God, who is the Creator of everything in the universe. who do we think we are, telling God that He cannot use evolution as the means of creating life diversity and species?
As a Christian, I can testify that allegorical interpretations of Genesis can be traced back to before the advent of Christianity, and that scripture itself lends support to those allegorical interpretations. In fact, there are two different accounts of creation in the first two chapters of Genesis, and each conflict in small but important details - for instance, in the first account, God creates both men and women on the sixth day along with the other large animals, after he has already created plants, the sea animals and flying animals, and so on. In the second account, we see a man, Adam, being created, and God puts him in a specific location.
Then God creates the plants and the animals, and brings the animals to Adam to be named. The very last thing God creates is the woman, Eve. In a literalist reading, which account should take priority, as each has a different order in which the creation is made?
The crux of the issue is that allegorical interpretations of Genesis are every bit as valid as literalist interpretations, and many prominent Christian theologians, such as Augustine and Origen, believed that Genesis was allegorical.
In closing, I wish to leave you with a quote as a final thought:
"It not infrequently happens that something about the earth, about
the sky, about other elements of this world, about the motion and
rotation or even the magnitude and distances of the stars, about
definite eclipses of the sun and moon, about the passage of years and
seasons, about the nature of animals, of fruits, of stones, and of
other such things, may be known with the greatest certainty by
reasoning or by experience, even by one who is not a Christian.
too disgraceful and ruinous, though, and greatly to be avoided, that he
[the non-Christian] should hear a Christian speaking so idiotically on
these matters, and as if in accord with Christian writings, that he
might say that he could scarcely keep from laughing when he saw how
totally in error they are."
-Augustine of Hippo, early 5th Century theologian in The Literal Interpretation of Genesis.