I have plenty of differences with Walter Brueggemann, but his sermon on Psalm 100 is very rich [“Psalm 100,” Interpretation 39 (1985): 65-69]. The following quote makes a profound point about praise and has helped me see more of the importance of praise.
To praise is to reject alternative loyalties and false definitions of reality. Praise is relentlessly polemical. As this God is affirmed, in the same act other gods are dismissed as irrelevant and denied any legitimacy. As Israel acknowledges to whom it belongs, it also asserts to whom it does not belong. The ones dismissed may be variously the gods of Egyptian enslavement, the gods of Canaanite manipulation, the gods of Babylonian imperialism; all these are now declared null and void. (66)
To lift up the one true God is to cast down all would be gods. We fight idolatry in our hearts with praise. And, when thanklessness creeps in, beware. There is an idol lurking. Unleash the cannons of praise!
But Brueggemann is really making a point about corporate, cultural claims more than internal personal issues. When we praise Yahweh, the God of Abraham, Isaac and Jacob, the God and Father of our Lord Jesus Christ, we are saying that all others, put forward as gods throughout the world, are nothing. This is strikingly countercultural in a pluralistic age. Praise is surprisingly subversive in a relativistic age. Praise then lays the groundwork for evangelism. Let us hold fast and advance by being people marked by hearty praise of our God and Savior.