I take the same approach that I do when Intelligent Design supporters claim that God created the scientific foundations and laws. It might be true that God is responsible for everything and not natural law, but if that's the case then the two are indistinguishable and it seems to be more practical and reliable to turn to science for answers instead of God. Like you said, I go with what is working.
As for my purpose and reason for living even if I do believe one day both my body and soul (whatever the hell a soul is) will die, I turn to my boy. 
When, without the bitterness of impotent rebellion, we have learnt both to resign ourselves to the outward rules of Fate and to recognise that the non-human world is unworthy of our worship, it becomes possible at last so to transform and refashion the unconscious universe, so to transmute it in the crucible of imagination, that a new image of shining gold replaces the old idol of clay. In all the multiform facts of the world--in the visual shapes of trees and mountains and clouds, in the events of the life of man, even in the very omnipotence of Death--the insight of creative idealism can find the reflection of a beauty which its own thoughts first made. In this way mind asserts its subtle mastery over the thoughtless forces of Nature.
...
The life of Man, viewed outwardly, is but a small thing in comparison with the forces of Nature. The slave is doomed to worship Time and Fate and Death, because they are greater than anything he finds in himself, and because all his thoughts are of things which they devour. But, great as they are, to think of them greatly, to feel their passionless splendour, is greater still. And such thought makes us free men; we no longer bow before the inevitable in Oriental subjection, but we absorb it, and make it a part of ourselves. To abandon the struggle for private happiness, to expel all eagerness of temporary desire, to burn with passion for eternal things--this is emancipation, and this is the free man's worship.
EPT
