Why not being honest?

Utilitarianism is against lying, stealing, and cheating. Why is not accepted? First of all because it affects the majority. A vast amount of people around the world has been stolen, taken away what they’ve hardly worked for. Some could say that thieves steal for necessity, I agree but not when it becomes a habit. I believe that everyone is capable of working, if they are capable of stealing then they can easily get a job and work to get what they want; not the easy way. Cheating is also rejected by utilitarianists. Why not create our own ideas, why not study hard for our tests instead of cheating the person beside us? Getting an A after a long night of studying makes us feel proud of ourselves. When we cheat we are not hurting others but ourselves, in the future we will be an unsuccessful businessman/woman because we have no knowledge, we didn’t realize that the person beside us wouldn’t be there for us our whole lives. Then what happened was that we lied to ourselves. Lying is another thing utilitarianists do not tolerate. We are always covering the truth with lies, lies and lies. Human beings never face the consequences of our actions, we always do what is the easiest thing. But you have to know something: lies don’t last too long, sooner or later we get caught and once again the ones who end up losing the most are us.

Why not being honest? Why we never do the right thing?