Why Do We Have Deacons? (Acts 6:1-6)

Acts 6 lays out a complaint which recalls for us the Old Testament tragedies when Israel complained against the Lord.  It seems as if the New Testament church is just like the redeemed people of Israel who can only complain about the Lord’s shepherding care.  Why is it that the Lord does not consume them?  Why is it that the Apostles actually concede and act on this complaint?