I don't know when my parents first taught me about sin and Satan's role in tempting me to sin, but I know I was young. I was about five or six years old the first time I sinned. I was with my mom shopping at Bed Bath and Beyond. Being the incredibly gay boy that I always was, I wanted a piece of scented soap that was carved like a flower and I asked my mom if I could have it. She said no. I put it in my pocket anyway, and that was sin.
She found the soap when she did laundry later--long after I'd forgotten about it. She made me go back to the store to apologize and pay for it. I think it cost a quarter. Then she explained that I had to resist Satan's temptations. He wanted me to do wrong so I would be miserable, and he would do anything to make that happen.
I remember in Sunday School learning that one of Satan's biggest tricks is convincing men that he doesn't exist. The theory was that if Satan could convince you that he didn't exist, then he could get you to sin because if you don't know there is an evil force whispering in your ear, you will just do whatever that evil force tells you to do. There is no accountability for your actions if you don't believe in Satan, or so I was taught.
In practice, I have actually come to believe the opposite is true. I have found that I am more accountable for my actions since I stopped believing in a literal Satan. When I was LDS, I believed that I sinned because Satan tempted me to sin. That meant that every misdeed came about because he intended me to do wrong. He wanted me to be miserable, and he wanted me to make others miserable. Sinning was because of him. That didn't mean I wasn't still accountable or that I didn't have to repent. I had still done wrong, but my wrongdoing was not the misdeed itself, the wrongdoing was succumbing to the wiles of the ultimate trickster. (And who hasn't fallen prey to him before?)
Somewhere down the line I stopped believing that there was a Satan. Maybe it was when I realized the consequences to actions were not as clear as I'd been taught, and that the rightness or wrongness of actions were not as black and white as I'd thought. Maybe it was when I stopped believing God was a man with a white beard. Maybe it was when I stopped going to Church, or started drinking coffee without feeling guilty. Whenever it was, I now feel more accountable for what I do because of it.
When I do wrong, I can't turn to the devil on my shoulder and say he told me to. I can't blame my desire to do wrong things on someone else. I don't believe there are temptations placed in me by some malevolent force. When I screw up, it is because of me. I stole that soap because I wanted it, and I didn't care about the store that I stole it from. I was selfish, and while it is easy to accept that my six year old self was selfish, the fact is I am still screwing up. It is much harder when I do something wrong now because the desire to do something wrong is my desire, and I have to look at myself to understand it.
It's really horrifying to realize that I want to do things that are bad. Not only do I have to choose not to do those bad things, I have to reconcile the fact that I want to do them with my belief that I am a decent person. Frankly, facing my desire to do wrong head on like that kind of sucks.
It was easier when I had an explanation for sin and for sinful desires. Then all I had to do was say no to this external force that wanted me to do wrong all the while taking comfort in the fact that I only wanted good things. That was easier. So much easier that I am seriously tempted to believe in Satan again, and unfortunately, I don't have anyone to blame for that.