How do we know that there will be another tommorow?

Sometimes I ask myself will there be a tomorrow?? How can we be certain of it? Is there some way that we can know?? There isn't always an open door ... Life I have realized is something sacred and we mustn't waste it away... because the future no one can see and today we are here and tomorrow we can be gone. We must just step aside and just live our life because tomorrow can just wash away like a chalk paint left in the rain. Don't put off the things for tomorrow that you can do today... we must take advantage of everyday because that moment is now and if we don't live it we might just regret it. As I sit here and just watch the snow fall down and can see the snowflakes melt just as they land on the window and that made me realize how our lives and moments can be they can be here for a split second and then the next thing they could be melted away. We must always have a reason if we don't then the moments could be gone. Life is now and it is here we can almost feel it. That's why we must put the negativity to the side and just live our life to the fullest because in a moment it could be gone. We shouldn't live in weakness and in fear. Our ability to taste the sweetness....we must taste it...life is real so we shouldn't ever fake it. We need to just live it and let it be. Because tomorrow could just wash away just how chalk on the sidewalk washes away under the rain. This moment is now.. none of of can see the future and what it'll be... we shouldn't wait or else it'll be to late and we will regret not living out life.