This symbolizes men trying to reach haven on his own terms. Trying to do things men's way and not God's way. No matter what we do, no matter how we might be big in the eyes of men it will mean nothing in the day of judgement if we are not ready to meet God based on His Word. The only way we will be accepted by God, is by doing things God's way. Our way means nothing if we fail to change our lives so that our lives line up with His Word. Jesus paid a great price (his life) and if we fail to accept His way, then we automatically eliminate ourselves from being candidates to go to Heaven. His way is the ONLY way!