The Agricultural Revolution (also known as the Neolithic Revolution) was undoubtedly a decisive point in human history. This was because agriculture allowed civilization to come into existence.
Without agriculture, there can be no true civilization. This is because, without agriculture, it is almost impossible to have either large populations or a sedentary community. You need agriculture so that there can be surplus food to feed people who are not actually making a living by getting food. These people can become artisans or teachers or government officials, thus creating civilizations. You need agriculture so that you can be sedentary. This allows more material culture. You can't have furniture or works of art or books or anything like that if you keep having to move all of your possessions as you move around because of your hunter-gatherer lifestyle.
For these reasons, agriculture led to civilization, thus making the Agricultural Revolution a tremendously important and decisive point in our history.