One thing that is essential to political activity is that it must always be what?

Civic life is the public life of the citizen concerned with the affairs of the community and nation as contrasted with private or personal life, which is devoted to the pursuit of private and personal interests.
Politics is a process by which a group of people, whose opinions or interests might be divergent, reach collective decisions that are generally regarded as binding on the group and enforced as common policy.

Politics is a process by which a group of people, whose opinions or interests might be divergent, reach collective decisions that are generally regarded as binding on the group and enforced as common policy. Political life enables people to accomplish goals they could not realize as individuals. Politics necessarily arises whenever groups of people live together, since they must always reach collective decisions of one kind or another.
Government is the formal institutions of a society with the authority to make and implement binding decisions about such matters as the distribution of resources, allocation of benefits and burdens, and the management of conflicts.

Differing assumptions about the proper relationship between civic and private life influence ideas about the purposes of government. Differing ideas about the purposes of government have profound consequences for the well-being of individuals and society. For example, if one believes that the activities of government should be restricted to providing for the security of the lives and property of citizens, one might believe in placing severe restrictions on the right of government to intrude into their private or personal lives. On the other hand, if one believes that the moral character of the individual should be a public or civic matter, one might support a broad range of laws and regulations concerning private behavior and belief.

Differing ideas about the purposes of government have profound consequences for the well-being of individuals and society.
Citizens need to understand competing ideas about civic life, politics, and government so that they can make informed judgments about what government should and should not do, how they are to live their lives together, and how to support the proper use of authority or combat the abuse of political power.