The biggest decision any person can make in their lifetime is whether or not to believe in God, His son, sin, Heaven and Hell, and Jesus' sacrifice. If they believe that God isn't real and they are correct, then no big deal. Your life is all you have, so live it to the fullest.
However, if they're wrong, and God does exist, if Heaven and Hell and sin and Jesus' sacrifice all exist then they are gambling not only their life <em>right now</em>, but also eternity. Think about that. You can't change your destination after you die. You would be willing to risk forever, eternity, never-ending sorrow and excruciating pain because you don't want to believe in God?
To me, that is the biggest decision you can make in your lifetime because it doesn't just affect your lifetime here, it affects your life after as well.
