Science seeks to understand how nature behaves by observing and correlating available factual information. Our understanding of science is therefore based upon, and limited by, the factual information available. In science, fact-based explanations are called "theories." Theories may be good, bad, or indifferent. It all depends on the accuracy and amount of the factual information available, and how logically these facts are interpreted. Consider the Piltdown hoax as an example: The fact is that a skull with a homo sapiens cranium and jaw bone of an ape was found in 1912. At that time there was very little factual information, in terms of similar fossils and radiological dating methods, available to corroborate whether or not Piltdown was a legitimate fossil. As additional factual information became available, scientists determined that Piltdown was a hoax.
The characterization of evolution as "only a theory, not fact" is a gross distortion of the meaning of the words "theory" and "fact." The term "fact" should be limited to what can be observed. It is the job of the scientist to determine the accuracy of this factual information and how it can be used to increase our knowledge of how nature behaves.
The natural sciences do not deal with matters involving religion, philosophy, and politics. Although evolution is incompatible with with some sectarian religious dogma, there is nothing in evolution that rules out the existence of God. Darwin's theory of natural selection has been falsely interpreted to apply to the philosophical concept of "Social Darwinism," which states that those who believe in the validity of evolution must necessarily support the politics of "might makes right."
Creationists believe that if a person believes that people are descended from primitive ancestors, he/she will behave as an animal, instead of an enlightened human being. There is nothing in the history of human events to support this allegation. It is bigotry, pure and simple.