We follow our whims when we are young unless we are stopped or sidetracked. Then, we change our strategy. We either become clever and deceitful to get our way or we conform and become group-think automatons. It is our essential character which makes us one or the other.
I consider this to be a very accurate statement. The main motivation for what person we are is our own nature.
The whole debate about free will versus determinism is never ending, like a dog chasing its tail. It is too complicated for me to get into right now. What I would say is that although many factors influence our behaviour we are at some level aware of what we are doing. We also have a good idea of the consequences that our behaviour will lead to if we are held accountable. To this degree we ourselves decide whether risk outweighs reward and then act accordingly.
To those who separate the sinner from the sin, If our body commits a crime in the physical world, then our body will be locked up in the physical world. If we choose to, we can separate our self from the sin and ponder on what we have learned in a prison cell.
People who do good works do not expect society to separate them from their charity and rationalise away the merit of their deeds. They are viewed as good people not people who do good because they are unable to help themselves.