Also, your firewall is managed and monitored 7x24 by security experts who know very well how firewalls work, how attackers work, and how to stop an attack very quickly. A firewall must be constantly managed and monitored. Like a building perimeter security solution, a firewall is only effective if it is constantly being managed and monitored by security experts. A building security system can't stop someone from putting a brick through your window. However, they can detect it.
Firewalls are the same.
When an attack is detected, someone must be available to response and take defensive action. Most security violations occur during off hours when no one is there to see them. Site Patrol is there 24 hours a day, and 365 days a year. A firewall, by itself, is only a tool. To make it a solution you need to operate it with security expertise, security procedures, and effect incident response.