I think to say someone "uses the Force"– while helpful in quick descriptions– is actually quite misleading.
Because when you really look at it, nobody actually uses the Force. The Force uses you. The Force works through you, both Light and Dark.
To follow the Light means to accept the will of the Force.
But many who "use" the Dark Side believe they can bend the Force to their own will. And when it comes to the Dark Side, this may be temporarily true, but that is the trap. That is what the Dark Side wants you to believe.
The Dark Side seduces you with the promise of control– of your fate, of the Force itself. Through the Dark Side, one can bend the laws of nature, can achieve unimaginable feats of power that those who choose the Light could not comprehend.
But these are breadcrumbs.
The Dark Side is a hungry beast that plays at being prey. It sinks its teeth into you, but you will never feel it as it placates you and distracts you, as it gets you drunk on pretty promises: you are in control, you can bend me to your will, take all you want from me. I impose no rules, no restrictions. I will serve you.
But the Dark Side serves no one, just as the Light Side serves no one.
There is no using the Dark Side, because the Dark Side uses you.
It consumes, until there is nothing left of you.
In the end, the extremes of both the Light Side and the Dark Side end in the complete obliteration of the self. With the Light, you expand your consciousness and understand that you are not you, you are simply one small piece of everything. In the Dark, you are slowly devoured, becoming smaller and smaller until you are nothing.
