The one who gives offerings must be willing, pure at heart and have pure intentions, and the one who receives the offerings must have pure intentions and be pure at heart as well. Thus both shall receive blessings.
Sharing, it's just like planting more seeds, and then it will grow more, grow more, and then you get some back, more than you have sown and then even left over, to sow for the next harvest, again and again. You never lose.
When we give anything to anyone, we are only fulfilling our obligation by giving what God has entrusted to us, to the rightful recipient.
We should do things without any purpose in mind. It applies to any job. Unconditional devotion is the best.