It has been an overly quoted concept that our destiny is influenced by three factors:
Heaven - one's natal chart, the qi structure of the moment of birth and the interaction with Heaven's qi thereafter;
Earth - feng shui of one's ancestral burial site and feng shui of the house for the person;
Man - what is in the person's mind and hence his action.
Some people then hastily conclude that our free will is responsible for 1/3 of our destiny.
There are three factors but it does not mean that each has a equal weight of 1/3. The weight varies with different people. The weight also varies with time.
For example, when someone commits suicide, it has nothing to do with Heaven and Earth. It is 100% the person's exercise of his free will. According to the natal chart, the person may have to deal with some very difficult situation. The feng shui of the house where he lives may have brought him very bad luck. It may even induce a self-destruction notion in his mind. However, it is his free will that causes him to commit suicide.
From the destiny chart we may be able to see that the person may destroy himself. This is not to be interpreted as committing suicide in the literal sense. This only points at the person doing something leading to his own destruction. He may do something to ruin his career, his family and himself. There is no problem that has only one solution - death although this sometimes may be the easiest solution.
Suicide is one extreme example showing our life is in our own hands. It may not be so with other situations. Talk to you later.