Here's the vision in the text: the valley of an army of dry bones. Ezekiel prophesies to them; then they come to life and are allowed to go home. First, an overview of the prophet Ezekiel's book: (1) judgment on Israel; (2) judgment on the nations; and (3) promises of restoration for Israel. Our text falls in the last part.
Look at the first two verses. The vision begins, lifelike. Who killed the bones? The answer (chapter 21): God Himself, through pagan nations. The bones stand for those physically and/or spiritually dead because of God's punishment for their relentless sinning. Now look at verse 3ff. Ezekiel prophesies to the bones - God breathes, as at Pentecost, His Spirit into the "very dry" bones, the totally spiritually dead. (At Pentecost, three thousand came to life, those who had cried out for Christ's death.) The bones then came together as complete, articulated skeletons, by the power of God's Word using Ezekiel's preaching. The Spirit is, we see, connected to the Word and Sacraments. No other means - these are the ones He uses. Don't mistake the gift for the Giver.
Next, breath is prophesied into the bodies. This "breath" is specifically the "wind of the Spirit of God." Compare to our Baptism - we, too, are resurrected to be warriors of God! We fight using the Scriptures to show others that there is only one path to God: Jesus Christ.
Finally, God tells Ezekiel to send the army home - they were formerly cut off from God (their own fault), but were now reconnected. Apart from the Holy Spirit, we are dead. But now we are His soldiers, for He has raised us and brought us to the new Israel. Live as a child of God, therefore, walking in the Spirit.
New upcoming sermon series: how to live as a Christian. Not what you'd expect from an LCMS church? Wait and see!