When people consider past events to be the result of free will they are filled with remorse and regret. When they consider future events as destiny, lethargy and inertia set in.
A wise person will consider the past as destiny and the future as free will. When you consider the past as destiny, no more questions are raised and the mind is at ease.
And when you consider the future as free will, you are filled with enthusiasm and dynamism. Of course there will be some uncertainty and some anxiety when you consider the future as free will, but it can also bring alertness and creativity.
Now, how do we remove the anxiety? By having faith in the Divine and doing sadhana. Consider the past as destiny, the future as free will and the present moment as Divinity.