I made a lot of mistakes in my life. Some deliberately while others due to naivete. But no excuses. I did a lot of bad things. Period.
Wrong things are called "wrong" that you have to make them "right" and not to make another one. Realizing that one thing is wrong is the first step to correct it. Acknowledging your imperfection does not mean you are to do more intentional wrongs or you have to tolerate others' mistakes.
A plane on auto pilot may deviate from the desired path but there's a locator mechanism which brings it back into the right direction just like how your morals and principles redirects you into doing the right things. And being wrong once does not diminish your ability to identify the sins of others. We have the responsibility to guard our actions towards other people and to guide, teach and call out those who are going astray.