Three things can happen when you look into the depths of nothing. That is, when you use pure human reason to divine meaning from the world.
1. You go bonkers and you kill yourself. Because after you dig and dig and dig with your mind you will find out that there is no meaning, no purpose, no heaven. We're all alone and nothing really matters in the end. You can't stand the thought of it, and you think to yourself, now's a good time to punch exit. Nothing's worth anything anyway. So you take the nearest window on the high floors and fly one-way to your final destination.
2. You go bonkers and you take it out on someone else. You stare into the depths of the unfathomable and you are surprised because the nothing has eyes and stares back at you. If you ever reach this point and you are scared sh!tless, now would be a good time to turn back and run like all the armies of Hell were chasing you. (You might not be far off the mark there too.) Because if you hold your ground and you cannot endure then you will find meaning, and you will find god.
They're just not the meaning and the god your grandmama is comfortable with.
3. You accept that your mind cannot extract meaning from life beyond a certain point. That not everything can be brought under your tight-fisted control. A light goes off in your head, and you find God. Or you achieve the enlightenment and positive engagement of life that some Buddhists and Nietzscheans find. Then you move on to do your job and eat your dinner the way all enlightened luminous souls are expected to.
Guess where I am hovering now.