Endurance is not just a nice spiritual quality to have, it is a necessity.  Matthew 24:13 states, "He who endures to the end shall be saved."  God doesn't expect anything of us that cannot be accomplished without His help.  If we try to endure to the end on our own, we will fall short, and falling short in this case would be a disaster.  But, with God's ever-present help, we will be able to endure to the end.