Agriculture allows a greate amount of edible food to be produced from an area than hunter gathering which until recently fed everyone. Why agriculture came to be developed is a complex question as agriculture generally takes more work than hunter gathering but it is thought that climatic disruption may have played a role. The greater amount of food agriculture provided allowed for fast population growth and a surplus in food production allowed for the development of a class of people that were not directly involved in the process of growing food eg artisans and priests. This seperate class was part of the development of hierachy which we see today but more about that later.
The need to irrigate crops lead to massive irrigation projects (eg mesopotamia) these projects required a high level of social organising in construction, maintenace and to regulate the use of irrigation water. This required either a coming together of autonomous groups to work together or a form of government.
The other major development which is of critical importance is sedentary communities, previously in a hunter gatherer society one could not hoard much wealth as one was moving frequently, and due to the types of foods most prevalant eg wild animals and fleshy crops food storage was difficult. This movement and lack of fod storage made giving away excess food and wealth a logical strategy, and in these sorts of societys status is often gained by giving things away.
The development of agriculture allowed for wealth to be hoarded through permanant communities villages and cities. For food to be stored through the use of domesticated animals and grains which stored well). For the development of a non labouring class through a food surplus. And agriculture often brought about a need for high level organisation for things like irrigation and for trade.
I would also argue that as well as the physical realities posted above Agriculture contributed to a spiritual alienation from the land with people switching from relying on the land to provide to fighting against it to provide food. This may be evidenced by religions such as christianity which place an emphasis on dominating and conquering the land.