I do not dispute free will. And yet there is an element of fate, as well. Let me ask you, if you make a choice, it is your, correct? You had free will, correct? But was this not fated to happen? Was it not your fate to make this choice, yours though it was? I think the idea of destiny does not mean that we cannot make our own choices (which we can indeed do; we certainly have free will), but, rather, that those choices are already predestined. I have noted before that both the religious and the atheists must believe in fate, and this is why. The religious believe in fate because they say that God knows all things, and therefore knows beforehand what choices we will make; this is fate. For the atheists who belive in science as their religion (and it is most certainly a religion), they too must believe in fate. For if you deny the existance of a soul, and we are but animals at the mercy of the choices of our mind...are not the workings of our mind dependent on the electrical signals? And are those not in turn influenced by the position of chemicals and such in the brain? This can be taken backward a thousand fold, and it could then be said that every action we do now is simply a result of the primordeal arrangement of atoms at the birth of the universe; all that ever was and shall be was set in that moment. So as an animal, and nothing more (which is what you must then profess to be), you are at the mercy of the universe, and have no true understanding, only instinct and survival. But enough of fate and predestination. Even within the Church predestination is a debated topic.
In regards to humanism and such, and the concept of Original Sin. You are thinking merely of sin in what you see and feel in your life and world. It is a deeper problem than this. It is the inherant flaw in all humanity, which does most certainly exist. If one were to take a child and put them into isolation at birth...would they grow to be perfect, thinking no evil? Would they then not know anger, or greed? No, they would. Why, then? Because of the inherently sinful human nature, and this human nature is the result of Original Sin. It taints our inborn souls, and drives us to evil. Moreover it is more insidious than this, as it tells us that the things of God are despicable, because they rely on strength other than our own. We are proud, far too proud, and wish nothing else to hold sway over our lives; and so we deny God. And all this feels very good in our hearts, because we think ourselves free of any domination of any sort. Yet this very feeling is that which betrays us; our own heart betrays us in this. Because the very thing which feels best is that which is worst. You may claim this to but theory, but think about this: how much do you really master your own destiny? Can you tell me that you will not die tomorrow in a car accident, or that you will not be suddenly afflicted by some disease? You cannot know. You can only look back, the future is a mystery. To try to be captain of your own destiny in such a manner is akin to captaining a ship through fog; you may be fortunate for a time, but what will you do when disaster strikes? What will you put your faith in on your deathbed when all your strength can no longer avail you, when all your knowledge is ashes?
The belief in the strength of humanity is also what has caused the worst atrocities the world has ever seen, I might add. Hitler, Stalin, Mussolini, some of the most dire leaders in history, upon whose collective hands are the blood of millions, were all people who did not believe in God but rather trusted in their own power; it too seemed good and mighty for a time. And yet it not only led to evil, but it did not last. They all found all too late that their power was worthless.
In reply to the quote you had, here is one from one of the masters of literature: "There are more things in heaven or earth, Horatio, than are dreamt of in your philosophies" -Hamlet. (pardon me if I missed some of the wording; I wrote it down from memory)
