As others have noted, rituals bind people together and the flip side of that can be that this cohesion may be used to exclude, or make the group more open to excluding others—-and beyond that, more ready to engage in some version of the Two Minute Hate. As a nation, we are too diverse to have many public rituals beyond the inauguration, celebrating July 4th, or in some places starting meetings, classes, etc. with the Pledge of Allegiance (a relatively recent and to my mind dubious ritual, if you look into its history). But numerous groups, from families and clubs, faith groups and schools and teams to ethnic and geographic communities, have rituals of their own.
The use of rituals is universal across cultures in history; obviously it fills a deep human need. But in our time, I agree with Candace that we must be mindful of the rituals we engage in, be alert to whether it is positive and does not carry any message that those outside of the group are less worthy, less deserving of respect, less than fully human.