Absolutely - that is why God gave mankind a brain and freedom of will, so we can use our brains and make wise decisions.
I do not think destiny is not written in the sand - otherwise the act of living and deciding would be pointless. We shape our own destiny by our decisions and actions. According to the will of God perhaps, but not according to God pulling strings on everything thing we do or that happens to us.
Likewise, I also believe that there is randomness in the Universe and that God is not nearly as hands-on as some might wish. To believe otherwise is to deny the obvious and to spend the rest of our lives pulling our hair out trying to understand the will of God and making hollow-sounding excuses about why airplanes with innocent children plummet to the ground or tornadoes strike churches and schools.