“I shall pass through this life but once. Any good therefore
that i can do, or any kindness i can show, let
me do it now. Let me not defer or neglet it;
for i shall never pass this way again.”
I think this quote is trying to say that you only have one life to live and you can’t waste your time doing nonsense. you must take action of your life and do all that is in your power to do something great or nice with it. Think of your acts of kindness as credits that will allow you to get the most out of life when it comes to an end. If you have a lot of these “credits”, it will will catch up like karma and will make your life easier and peaceful.