Determinism vs. Existentialism

So this summer I struggled with the concept of whether or not people could really change, and it's been brought up again because of Eric (in my novel) and the fact that we are talking about determinisn and existentialism in Core 250, so I feel the need to revisit the subject.

It seems to me that people generally don't change. Someone behaves in a certain way, and they stay that way. People don't just get "nice" all of a sudden. A leopard can't change his stripes, a "former alcoholic" is just an alcoholic waiting for an excuse to go back. And so my intial thought it that people can't change. A sad fact of human nature is that you can't go back and change your life. It doesn't work that way. It all felt rather cynical to me, and I liked it that way.

But then, there is always the exception. There is always the person with the troubled past, with the bad mistakes, who uses those mistakes to learn and grow and become a better person, not devoid of the past, not forgetting it, but constantly aware of it and using it as a reminder of what used to be and of what should not be returned to. And I realized that people can change. Isn't that the whole point of Christianity? With God's help we can live a new life, free from the sin we were once entrapped in?

But then again, what about my original observation? That people who did an undesireable activity always turned back to it? Even after they promised to change, it always drew them back, and they fell under it again? How could that be accounted for if people are free to change? And then it hit me.

People CAN change. They can leave behind the past, use it to learn, become a better person, do good instead of evil. They can. But they don't. Every day you're alive, every day I'm alive is an opportunity to change for the better. It's all there to reach up and grasp. People CAN change, but they DON'T. Even though it's so simple (notice I didn't say 'easy') they choose instead day after to day to remain the same. And I think (though some have disagreed) that this idea is far more depressing than the first. It's not that we CAN'T change that makes me wonder about the decency of humans, it's actually that we CAN.