If you're preaching on Micah 6, don't fall into the trap of juxtaposing ritual and politics or similar. "God doesn't want liturgy, God wants justice." We can leave aside the oddity of liturgists earnestly proclaiming this (which will doubtless happen in great number).
Micah's message is that the Assyrian threat to Israel and Judah is not just about incidental geopolitics but about issues within their own society; the Assyrian threat is God's judgement on pervasive inequality and injustice.
Sacrifice was an economic activity, even though God is an actor in the economy, as both provider of goods and recipient of them, in sacrifice. And in fact Micah isn't talking about "sacrifice" but about one type of offering, the radical 'olah or whole burnt-offering - or, chillingly, "holocaust" in which humans do not share. While more often sacrifices were feasts, these imagined devotees are accused of offering God their wealth in great quantity when the prophet has already conveyed the nature of the divine complaint as somewhat different:
"They covet fields, and seize them;
houses, and take them away;
they oppress householder and house,
people and their inheritance." (2:2)
Tellingly, Micah compares this exploitation to devouring the poor:
"you who hate the good and love the evil,
who tear the skin off my people,
and the flesh off their bones;
who eat the flesh of my people,
flay their skin off them,
break their bones in pieces,
and chop them up like meat in a kettle,
like flesh in a cauldron." (3:2-3)
So when the critique juxtaposes offering 'olah sacrifices with justice, this is not contrasting religion and economics, but economics and economics or religion and religion. The food
envisaged as offered to God was the product of exploitation; it needed to be shared with the hungry (even perhaps via the more communal form of sacrifice, the zebach - see Lev 3). Nor does Micah reject sacrifice at all; he rejects the substitution of this particular ritual for the religious duty neglected, but still envisages Jerusalem - the city of the Temple, above all - as the heart of Judah's ultimate renewal.