In a way, when a lawyer-client relationship is created, the lawyer has agreed to accept your legal situation as his own. Few times in your life will you be required to develop the kind of relationship with another person like the one you must have with your lawyer. You may be required to share details of your life that you would not discuss with any one else. With the help of your lawyer, you may be making decisions that will profoundly affect the rest of your life. Well, almost absolutely.
Lawyers have an ethical duty to protect the confidences and secrets of their clients.
There are a few very rare exceptions. So, do not take a murder weapon to your lawyer and ask him to keep it a secret from the cops. To best serve your interests your lawyer requires an honest client. You have to share the whole story, even the not so pleasant stuff. Likewise, you should expect your lawyer to be honest with you, even when that truth may hurt.