Well, things are just as weird as ever. Now, suddenly, Harry is seeing things. Strange dreams of running through long hallways. When one of the dreams involves Harry, as a snake, striking Mr. Weasly, his best friend's dad, he gets more than a little concerned. He tells Dumbledore, and they find that it indeed happened. Now it's become apparent that these aren't just random dreams, but Harry's connection to Voldemort is actually allowing him to see into Voldemort's world. This Voldemort eventually uses to his advantage, placing a fake vision of Sirius Black being tortured. Harry and his friends rush to his rescue, only to find him not there, but rather an ambush of Death Eaters. They fight as best they can, eventually being aided by the Order of the Phoenix, but the battle cost Sirius Black's life (probably the lamest occurrence in the series). Following this, there's a showdown between Voldemort and Harry, where Dumbledore steps in. Voldemort tries to possess Harry's body, but Harry is able to resist this. When all is said and done, enough of a warning has been dent out that many prominent members of the Ministry, including the Minister of Magic himself, were able to show up and see for themselves that Voldemort was in fact back and in power.
The plot just keeps thickening in this very exciting, and rather sad book. No one wanted to see Sirius die... he was Harry's best shot at a normal life. I guess Harry just wasn't meant to have a normal life.
The Order of the Phoenix (possibly one of the coolest named organizations ever) plays a major role in the second war with Voldemort, and we're told it played a pretty big part of the first war, too. This group of dedicated individuals are willing to risk life and limb to stand up for what's right and try to stop evil from conquering. They're unified in their purpose and are willing to do anything to accomplish their goal. This is how the Church is. We are the best form of protection from the world, because we have the best resources to combat the evil out there. We have the fullness of the Gospel; we have the Bible and Book of Mormon, that go together to answer all questions and provide an entirety of doctrine; we have Prophets and Apostles who reveal God's will for us, and let us know how best to get through life's maze. Thanks to these tools, we are never lost, and can be a guiding/protecting force for all our brothers and sisters. If they don't know the way, at least we do, and we can do our parts in helping and protecting them. That's what we as member's of Christ's church should do: reach out and "lift up the hands which hang down, and strengthen the feeble knees" (Doctrine and Covenants 81:5).