Give and you shall receive

Whatever you choose for yourself, give to another.If you choose to be happy, cause another to be happy.If you choose to be prosperous, cause another to prosper.If you choose more love in your life, cause another to have more love in theirs.
Do this sincerely—not because you seek personal gain, but because you really want the other person to have that—and all the things you give away will come to you.

Why is that so? How does that work?

The very act of your giving something away causes you to experience that you have it to give away. Since you cannot give to another something you do not now have, your mind comes to a new conclusion, a New Thought, about you—namely, that you must have this, or you could not be giving it away.

This New Thought then becomes your experience. You start “being” that. And once you start “being” a thing, you’ve engaged the gears of the most powerful creation machine in the universe—your Divine Self.Whatever you are being, you are creating.The circle is complete, and you will create more and more of that in your life. It will be made manifest in your physical experience.This is the greatest secret of life.

- Summarised from the book " Friendship with God" - Neal Donald Walsh