They are important because they are rooted in history.
When you look at both biblical lament and biblical celebration, especially in the psalms, they are rooted in historical context. They reach back into their history. They remind themselves and their listeners (their co-mourners/co-celebrants) that what they are experiencing has deep roots going back generations.
There were two primary ways that the lament and celebratory psalms root the people in historical context. First, they connect their cries of either celebration or frustration with other moments in time in Israel’s history when similar things were happening. Second, they root their song to the historical context of covenant especially God’s covenant promises either calling God to make good on them and deliver from trouble or celebrating them in the moments it is most clear that is exactly what God has just done in their presence.
In a world and culture that doesn’t value historical context and the identity formation that is produced from it we need to embed our lament and our celebration in the context of our history with God and our historical identity as God’s people who are guaranteed God’s promises. Today we weep due to the immediacy of the trials we face with little thought as to how generations before us went through similar things. Today we celebrate due to the immediacy of the joys and victories we experience with little thought as to how generations before us went through similar things.
It is time we begin rooting our experience in their experience and come to appreciate the value of a faith at its best when it is embedded in its own historical context as the past and present people of God.