Evolution is a theory that arose after hundreds of years of studying living and fossil organisms and explains their relationship over time. It does not mention god and is based on what we have found on Earth.
Creationism is a theory that states that a god created the universe. This god made the Earth, the stars and all living organisms. But the theory of creation does not address the existence of god. We can either think about god and consequently have a theory about god or just believe god exist and exert no further thought. I would argue that if we teach science students a theory that our universe was created by a god we should also have a theory of god. To teach science students that a scientific method of studying things is the best way to understand them and then teach a theory of our existence based on a god that is beyond contemplation is crazy. If you do not understand god then how can you accept a theory of creation which is based on god?
So the theory of creation, if it is to be taught in science, should include a theory of god. To develop a theory of god we need to first think about what god is. I think everyone would agree that if there is a god then god must be something as opposed to nothing. This something that god is may not be matter as we know it but something nonetheless. So the first part of our theory is that god is something.
What is the relationship between god and something? We have learned that people are composed of multiple tissues and tissues are composed of multiple molecules and molecules are composed of multiple atoms. So one possible relationship is that god is composed of smaller more fundamental units of something. In this case god could have parts - say a part to think about creating the universe and a part to create the universe. But this theory also says that there are fundamental units of something that are not god. God is the composite of these smaller units of something.
The other possibility is that god can not be broken up into smaller units of something. In this case god would be a single, homogeneous, indivisible unit of something. God would have no parts. And if we believe that there is only one god then there could only be one fundamental unit of something because if there were multiple units there would be multiple gods - one god for every fundamental unit.
So which theory seems more reasonable. It would be impossible with our knowledge of the universe to describe the capabilities of god in terms of a single fundamental unit. In the theory of creation god made man and woman. God made land, sea, and air. These are all different things. A fundamental unit of something would not have parts. We would need an additional theory to explain how a single indivisible unit of something would have the capacity to create a universe filled with different things.
If we assume that god is composed of smaller, more fundamental units of something then god would be capable of more complex actions like thoughts and creating universes. But now something exist not only in the complex form, god, but in smaller units which are not god. So god and something would be different. In addition to our theory of god we will need a theory of something.
Next we ask how long god and the something god is made of been around? If god and something had a beginning then we would need a theory of how god and something came to be. If god is composed of smaller units of something then could these smaller units of something been around before god? If this were true then god would have developed from these smaller units of something over time. Our theory of god would therefore contain a theory of evolution of god.
Assuming that god and something have been around forever eliminates the need to understand such a beginning or evolution. But if we assume that god and something have been around forever we now need a theory of why god, after an infinite amount of time, decides to create the universe. We would also need to define the universe as everything we know exist minus the something that god is composed of since god could not create himself / herself.
What about a theory that the universe is filled with something which has been around forever but does not form a god. We still do not know what this something is but we know that it can form both energy and matter. And through scientific methods we know that energy and matter are related by the equation E = mc2. We also know through scientific methods that the Sun will not burn forever. The energy and matter of our solar system will form something else in the distant future but for now they form the Earth, the Sun, and us. What is so terrible about that?
The theory of evolution explains the connection of man and other current life forms with distant life on earth. It is based on physical evidence we have found on our planet. It does not attempt to explain the origin of the universe.
The theory of creation is not a theory but rather a story of how the entire universe was formed. The story¹s main character, god, has been around forever, is all powerful and all knowing, and made the universe. God then placed mankind on a tiny little rock called Earth and keeps track of our actions and deeds. After we die we will go to either heaven or hell depending on how we lived on Earth.
The story of creation tells people that if they are good they can spend forever in the perfect place, heaven. Your life on Earth is but a stepping stone to the life hereafter if you lead a good life. But there is no physical evidence on Earth or in the universe to support this story. It is unfortunate that people need to believe they can live forever and need to believe they are part of a bigger world in order to give their life meaning. Appreciate your life more because you do not live forever and are only part of this world.
Science classes are a place where students should be taught what mankind has learned by studying the universe in a scientific way. If creationism is taught in schools it should be restricted to literature classes where other classic stories are told.