I'll give it a shot:

We know that we make bad decisions all the time. Sometimes we know when we do or shortly afterwards, such as when we make a decision while angry or in sorrow. Sometimes we don't know, like when we lack information or have flawed reasoning. But we know mistakes can be made.

Science is a method of avoiding mistakes and making good determinations. It isn't a magic ritual that makes us always right, but rather a system which forces us to establish what we know, to prove it with methods designed to figure out of we were mistaken, and explain exactly why we think we are justified in thinking the way we do. And finally, perhaps most importantly, it means we need to publish our work and have it checked by others in our place. They will look for errors, forcing us to be as good as we think we are. We all keep each other honest and true.

This method, science, has determined that evolution by natural selection is the best answer to the diversity of life we can see on our planet. It is supported by interlocking observations and explanations across dozens of professions, combining the work of millions of people into a cohesive whole. We can see the gradual progression of life forms, seeing where they diverged and when certain traits developed, from the evidence left over from the past and can observe the process ongoing today.

Every step of the way the scientists involved are using that method; they are constantly considering that they might be wrong and justifying their positions, daring their peers to find a mistake or flaw in their work. And to their credit they often do find such flaws, calling them out and bringing them to task. But the result of all that toil is our current understanding of evolution, still an ongoing work but quite useful in its current form.

My religious beliefs are personal, really having no place in this conversation, but yours are not. Not personal, and also not irrelevant because they are blinding you to the truths the scientific community has painstakingly established. You deny the conclusions of the work of science based on your faith, which if I understand correctly is "sureness in things unseen". This is contrary to our method of science; "seeing is believing" is more our creed. "Show me", "prove it", and academic rigor are the rules I respect, and the rules that led me to reject your faith as well.

So I ask you, can you prove to me and everyone else that your view is right? Can you show me the evidence, from minerals clawed from the ground, from field work observing thousands of creatures in their native habitats, from the building blocks of our bodies themselves? If you can then I will believe with you today, and the scientific community will shower you with praise and no small amount of material wealth.

But you cannot, of course. So I will thank you to sit quietly and attentively in class while I explain what our work has shown to be true as far as we can prove, and you can indulge in what you would like to believe in your own time. Understand that I'm not here to force you to believe, only to make you ready to represent this University properly. If you aren't up for it you can believe what you like, and I will fail you from this course. That is your choice to make, and I suggest you make it before your grades slip further.