G-d designed us in a way that we would need sleep to keep healthy and strong. He could have made us like the cel phones. In a way that we could just recharge and keep working or doing things meanwhile. Why did He create us then with the need to sleep? G-d in His infinite mercy and kindness willed it this way so we could have HOPE. As bad as today might seem, the day has an end and we can always say “tomorrow will be better”.
There was a holocaust survivor in our Shul. Once he was asked “how did you manage to survive the horrors of the concentration camp?” And he answered “I would always tell myself, tomorrow will be a new day and hopefully it will be better.”
