Dreaming without doing is like like sitting in your car, revving your engine but never putting the car into first gear. You eventually run out of gas and you're still in the same place. The only thing you've done is produced a lot of smoke.
Doing without dreaming is like driving around without a destination. Since you don't know where you're going, you have no idea when you have arrived so you keep driving around. And then you run out of gas. And guess what, you find yourself in the middle of nowhere - having to ask strangers for help.
To dream and not do is blasphemy. If you only exercise the imagination and never the execution, eventually your execution muscle will atrophy and you'll be nothing but a dreamer.
To do and not dream is drudgery. If you only execute what's in front of you, and never elevate your mind to possibilities, you will atrophy your imagination and soon enough you'll be one of those tight, dull parents telling their kids: "Son, life is what it is. Keep your day job, take your vacations and wait for your pension".
Dream and do.
Do and dream.
That is the way to make your life a masterpiece.