How can we combine these seemingly opposing attributes in one practice?
The answer is that there is a balance between effort and surrender in all that we do. Yoga teaches that we must fully engage in life, live wholeheartedly and try our best, but that this should be balanced by acceptance of the fact that none of us has control.
Asana teaches us a lot about effort and surrender: if we come to our mat with too much effort, there is a hardness to what we do, a sense of striving for something other than what we find in ourselves. With too much effort we lose the fluidity of our practice and the joy of yoga. If we come to our mat with too much surrender, then we might not bring enough fire to our practice; we might find ourselves giving up on poses instead of committing to our best version of them; there might be a passivity to our practice, a sense of not really giving it our all.
The idea is that if you can balance these qualities simultaneously while you practice, you’ll create a state of internal equilibrium that you can call upon when faced with life’s everyday challenges.
Think of a bird for example, after using enormous of effort in planning its flight, taking off and gaining the height it needs, if it did not surrender and use the power of the wind it would never make it.