When I first got to the rooms of Narcotics Anonymous, and I saw the word "moral" in step four, I almost said "fuck it". My problem with morality is that too many people try and force their ideas of morality onto others.
Too many times throughout history, there have been attempts to legislate morality. The debate still rages today, with ongoing battles over all sorts of pseudo-political issues that are actually issues of personal choice. Just look back at what happened when they tried to legislate morality with Prohibition. Prohibition bred a whole new set of problems, the most notorious and lasting of which was organized crime (Al Capone, anyone?).
Ultimately, morality can't be legislated. Morality is a matter of personal choice, personal beliefs, personal faith.
When I started realizing that Narcotics Anonymous is a spiritual program, rather than a religious or moral one, I became more able to open up to the steps.
When I behave in a spiritual manner, I quit worrying about what other people may or may not be doing and whether or not it is moral or immoral. I begin worrying about whether or not my own actions are spiritual or not, and I begin realizing that I have no control over what others do or don't do. I quit judging others for their personal choices, and I learn to forgive myself for my own past bad choices.
So when I hit that fourth step that calls for a "fearless and searching moral inventory", I look deep within myself and take a fearless and searching spiritual inventory.
The 12 steps of Narcotics Anonymous help me find my way to a spiritual life. I'll take a spiritual life over a moral one any day; there's so much less fear involved.