Nothing wrong with it. But.... The use of "should" along with "wise" is repetitive. Think about it. Our actions mark our destiny. Therefore be wise!

"Our actions define/direct our destiny; that's why we should remain wise." I'm not sure if "mark" was the right verb, but it was fairly close.

I like the use of the word "mark". Destiny is something preordained. We need to look for the signs of our destiny as they are manifest in what we do. We need to sense and read what these actions tell us about what we are supposed to do to fulfill what is expected of us. I might amend the second part to say that is why we must be self-aware. Self-awareness is a form of wisdom.