There is no Fate/Destiny.
It's Free Will, Probability and Proximity
We are born into this life and this life is all there is. This is it!
We are born because, once upon a time, a man's sperm fertilized a woman's egg to form an embryo which, during nine months developed into a human-infant.
Now, every single life is a chance occurrence. It is just one of the probable outcomes of a sperm reaching within the proximity of an egg. No, you and I weren't "meant to be" born, weren't "supposed to be" born. We are just probabilities that were realised.
So that brings me to the question, "What is Fate/Destiny?"
Fundamentally i see no difference between the two, conceptually. In my understanding, fate/destiny means, the path that a life will take and all the points along the path and in the end, the destination, are "meant to be/supposed to be". That our lives are pre-planned, even before we have our first thoughts.
So, who planned it? The obvious answer is an intelligent creator, that is God.
And it is here that the problem lies.
So that means we have no control over our actions or their consequences? We have no free will?
That we are mere actors playing our parts out of a script which is fixed and can't be changed by us? And no matter what we do, we will be what we are meant to be?
Now there is an interesting paradox i'd like to discuss here, very briefly.
Consider that you invent a time machine and then go back decades into the past and tell a scientist how to build a time machine. And so he builds one and you return to the present.
So, who invented it first?
You, since you came up with the idea originally or the scientist, since he built one years before you were born?
Similarly, suppose you are destined to become a sports legend and you do become one. Did you become one because no matter what actions you took throughout life, you were meant to be one or whatever "seemingly random" actions you took weren't really random and made you the legend that you ultimately became?
In order to prove which one is true and which one is false. In the case of time travel, we can't be sure since time travel is not possible right now and hence no one has traveled through time.
In the case of destiny, there is some proof of it being false in the fact that the decisions we make and the actions we take, in general, define how are life turns out, not including the "luck factor" -which depends on probability (likelihood of an event) and proximity (or distance from that event).
For example, if i don't study for an exam, i will fail it. And if i want to score really well, then i have to study hard. There are no two ways about it. The consequences depend on the actions i take. And i take the actions that i do, because i "will" to take them.
To a certain extent, i can't control what situations or different options come my way. But i have full control over my actions and decisions regarding those situations. Because I "will" my choices. I don't follow any intelligent design set aside for my life by some "God".