How to do all things:

At any given moment in time, we are what we are; and we have to accept the consequences of being ourselves. Only through this acceptance can we begin to evolve further.
[...]
In general, mankind almost always acts with attachment; that is to say, with fear and desire. Desire for a certain result and fear that the result will not be obtained. Attached action binds us to the world of appearances; to the continual doing of more action. But there is another way of performing action, and that is without fear and without desire.
[...]
People often confuse non-attachment with fatalism, when in fact, they are opposites. The fatalist simply does not care. He will get what is coming to him. Why make the effort? But the doer of non-attached action is the most conscientious of men. Freed from fear and desire, he offers everything he does as a sacrament of devotion to his duty. All work because equally and vitally important. It is only to the results of work - success or failure - that he remains indifferent. When action is done in this spirit, Krishna teaches, it will lead us to the knowledge of what is behind all action, behind all life: the ultimate Reality. And, with the growth of this knowledge, the need for further action will gradually fall away from us. We shall realize our true nature, which is God.

Appendix II, The Gita and War
Bhagavad-Gita: The Song of God
translated and appendix presumably written by: Swami Prabhavananda and Christopher Isherwood

.........

"My God, give me the grace to perform this action with You, and through love for You. In advance I offer to you all the good that I may do, and accept all the difficulty I may meet therein."

The Direction of Intention
St. Franis DeSales

Going to Salesianum (House of DeSales) High School, I had to say this at the start of every day and every class. Simple and profound, and highly compatible with the above sentiments.

Life of human invention

"Laws of nature are human inventions, like ghosts. Laws of logic, of mathematics are also human inventions, like ghosts. The whole blessed thing is a human invention, including the idea that it isn't a human invention. The world has no existence whatsoever outside the human imagination. It's all a ghost, and in antiquity was so recognized as a ghost, the whole blessed world we live in. It's run by ghosts. We see what we see because these ghosts show it to us, ghosts of Moses and Christ and the Buddha, and Plato, and Descartes, and Rousseau and Jefferson and Lincoln, on and on and on. Isaac Newton is a very good ghost. One of the best. Your common sense is nothing more than the voices of thousands and thousands of these ghosts from the past. Ghost and more ghost. Ghosts trying to find their place among the living." [Robert M. Pirsig, Zen and the Art of Motorcycle Maintenance]

Absence of independent existence

"Look still deeper into impermanence, and you will find it has another message, another face, one of great hope, one that opens your eyes to the fundamental nature of the universe, and our extraordinary relationship to it.

"If everything is impermanent, then everything is what we call 'empty,' which means lacking in any lasting, stable, and inherent existence; and all things, when seen and understood in their true relation, are not independent but interdependent with all other things. The Buddha compared the universe to a vast net woven of a countless variety of brilliant jewels, each with a countless number of facets. Each jewel reflects in itself every other jewel in the net and is, in fact, one with every other jewel."

"Nothing has any inherent existence of its own when you really look at it, and this absence of independent existence is what we call 'emptiness.' Think of a tree. When you think of a tree, you tend to think of a distinctly defined object; and on a certain level, like the wave, it is. But when you look more closely at the tree, you will see ultimately it has no independent existence. When you contemplate it, you will find that it dissolves into an extremely subtle net of relationships that stretches across the universe. The rain that falls on its leaves, the wind that sways it, the soil that nourishes and sustains it, all the seasons and the weather, moonlight and starlight and sunlight--all form part of this tree. As you begin to think about the tree more and more, you will discover that everything in the universe helps to make the tree what it is; that it cannot at any moment be isolated from anything else; and that at every moment its nature is subtly changing." [The Tibetan Book of Living and Dying, Soygal Rinpoche, pg. 37.]