Living Stones

Once again, the first reading and the Gospel share a powerful connection. This time, it's the Temple itself. Both stories take place at the Temple of Jerusalem (the one place on earth where sacrifice could be offered to God), and both begin with a situation of desecration, which would tell you that ultimately both passages are about the rededication or re-consecration of God's house. Whereas the Maccabees were able, in their time, to carry out their plans to the full, the Gospel just gives us part one: Jesus, in a prophetic gesture, drives the merchants out of the Temple precincts and teaches there. The consecrating sacrifice comes later, though it is hinted at in the plans of the "leaders of the people who were seeking to put him to death."
Why is the Temple so important?
In the Old Testament, as well as in the New (especially the letter to the Hebrews and the book of Revelation), the Temple is a replica of God's real dwelling, Heaven. This is what the Mass presumes, too. In the early Church not just the catechumens, but also people doing public penance (and anyone who was not able to receive Communion) were all dismissed after the homily. You were entering a consecrated zone (a kind of transcendent non-geographic place): If we didn't get that message before then, the Sanctus would tell us as much: "Holy, Holy, Holy!" Just another way of insisting that (in the words of the Eastern liturgy) the "holy gifts" are for "the holy (consecrated) people."