Giving does not impoverish us in the service of our Maker, neither does withholding enrich us.
(Science and Health with Key to the Scriptures by Mary Baker Eddy p79: 31)
God gives the lesser idea of Himself for a link to the greater, and in return, the higher always protects the lower. The rich in spirit help the poor in one grand brotherhood, all having the same Principle, or Father; and blessed is that man who seeth his brother’s need and supplieth it, seeking his own in another’s good.
(Science and Health with Key to the Scriptures by Mary Baker Eddy p518: 13)
Christian Science Canberra 
what a blessing these reminders are, and so true
So very true – the world is not a ‘zero sum’ game.