Think about the complexity of a single gene. It contains so many features--thousands of bits of data--each of which had to be acquired by mutation. But the tiniest worm on Earth could not have evolved from a one-cell organism in four billion years even if there had been a mutation in every one of those millionths of a second.
Mathematically impossible. Even if the Earth had been created at the moment the universe was created (and it wasn't), about 20 billion years ago, that tiny worm still doesn't have a chance. Neither do humans. So the theory of evolution as it stands is wrong.
Creationism, well, I could go on and on but you don't seem Christian. Many Christians believe that there is plenty of evidence, but it all depends on your perspective. We might believe in luck and skill, but some Christians (such as my mother) believe that every good thing is a work of God. Be it a sunny day or narrowly escaping death, Christians believe that these events are proof of God's existence.
Sorry for going on for so long. As far as you're concerned, you can go along with the evolution theory, as long as you remember that it is only a theory. Believe whatever you want. Be logical or spiritual, have it your way.
To answer your original question, you don't have to listen to the other people about "competent teachers" just because they believe the theory of evolution. There is no solid proof. Your teacher wanted to regain control of the classroom by trying to please everyone. The textbook can provide some evidence that supports the current theory, and for the tests you need to pretend that you buy it, but if your teacher doesn't buy it 100% and he shares that with the classroom, that's okay.