To do what you love means you'll never feel the drag of work, the long days and long nights in the office, the droning meetings in the conference room. To do what you love means you'll always enjoy and find purpose in what you're doing.
According to many people nowadays, doing what you love won't get you the kind of money you want. If we live with that mindset, though, we are centralizing money in our way of life instead of happiness. We were not put on this earth to build a Donald Trump empire; we were put here to learn, to live, and love one another.
As a Christian who has grown up in church, I believe that we were put on this earth as God's gift; a gift of struggle, lessons, and above all happiness, but it seems to me that we have seen the first two and decided to turn upon the third. This meaning, we see the struggle of this world and recognize that there are lessons we must learn, and begin to think that this is not the way we want to live. We want to go straight for that happiness without standing through the trials.
This is not the way things must happen, though. To understand where happiness really comes from, we need to understand that we must withstand the struggles on our way there because it is only through the struggles where we find our happiness.
Round this back to doing what you love. Suppose you have a regular 9 to 5 job, or maybe you have a demanding all hours job. Are you enjoying your time wherever this job takes you? Or are you just there to be paid and get on with it?
For me, I've fallen in love with photography, writing, and art of any kind. In result of this, I am seeking a journalism career, learning the ways of photography to supplement this, and aiming my writing towards the pursuit of an artistic lifestyle and I absolutely love it. It brings me comfort to know that whatever I may do with my life is grounded in these three attributes to my lifestyle because I know that they will lead me to my happiness and benefit society too.
What is the purpose of having a job you don't even like if it doesn't bring you happiness? Think of it as a spiral that starts with a disliked job. You spend most of your day, most of your week, for 40+ weeks a year at this job. When it comes down to it, this is your life. If your spending this time unhappy, you're spending most of your year unhappy, year after year. A spiral effect.
So do what you love, do something that brings you happiness. Imagine the type of place the world would be if we took this mindset? Less war? Less pain? Let's find out.