Yoga can help us gain better control over the raw energies that flow through us. Naturally occurring mental, physical and metaphysical nadis (energies) can be chaotic and distract us from the inner peace and contentment that already exists within us.
The external world is beyond our control; we owe it to yourselves to accept it for what it is. The truth is that pain is inevitable, but suffering is a choice. When we resist, we are deciding to suffer. The practice of Yoga is one means of choosing not to suffer.
When we seek that place within ourselves that is unaffected by the waves on the surface of our mental lake, we can remain grounded in our souls and refuse to let the external world steal our joy. This does not mean that the actions of others should be without consequence or that external factors are not painful, but ultimately only we can choose which thoughts and feelings we want to dwell in.
Our reality is that we feel and think and experience our lives based on many external factors. Remember that our power is deciding who we want to be based on how we act and react. Yoga helps us become more mindful and mindfulness helps us control our energies.
Thus, Yoga is practicing and honing our greatest power as humans.