Yes, conflict is inevitable in every society. This does not mean that conflict always has to be at high levels, but it is not possible to have a society without conflict. The major reason for this is that people in a culture or a society will inevitably divide themselves into groups and these groups will eventually come into conflict.
In the US, for example, we divide ourselves into racial and ethnic groups. We tend to believe that people of different races are in some way different from one another. We tend to believe that people of different races have different political and economic interests. This brings us into conflict on racial and ethnic grounds.
But conflict will exist even in the absence of racial and ethnic diversity. People in other societies (and in our own) will divide themselves on the basis of class. People tend to believe that the rich and the poor or the poor and the middle class have different interests. Because they believe this, the classes will come into conflict with one another.
People in every society will find ways to divide themselves into “self” and “other.” This will inevitably lead to some degree of conflict.