ISIS vs The Crusades

The Crusades were a string of military campaigns against Muslims to reclaim the "holy land." A lot of bad things happened in the name of religion to include rape and pillaging.
Recently Obama made a few comments in a speech comparing the movement of ISIS to the Crusades. Christians were quite up in arms about it too.
Many believers around me were quick to discount the comment because the Crusades weren't a representation of "true Christianity."

Joshua 1

11 “Go through the camp and tell the people, ‘Get your provisions ready. Three days from now you will cross the Jordan here to go in and take possession of the land the Lord your God is giving you for your own.’”

The book of Joshua is all about the purported original military campaign to claim the "holy lands" orders by God.

Joshua 8

2 You shall do to Ai and its king as you did to Jericho and its king, except that you may carry off their plunder and livestock for yourselves. Set an ambush behind the city.” (That’s God talking)

Later in chapter 8 they kill all the women and children by burning them alive in their city.

Joshua 17

13 Now when the people of Israel grew strong, they put the Canaanites to forced labor, but did not utterly drive them out.
(BTW this isn't what God said to do, but he did command Moses to do it.)

Now fast forward to the Crusades, a series of holy wars to reclaim the "holy land" back from Muslims which had conquered the area. Immediately, the plan sounds very much the same as what God instructed the Israelites to do in the Bible. In both instances it seems like terrible things were done in the name of God. How do Christians know the Crusades weren't ordered by God? What makes them so sure that those who took up the religious war in the name of faith were not doing God's work?
Most religions are quick to give their deity glory for things which are favorable to them, and even quicker to blame whatever does not on the human element of their belief system, but here we have a very clear case where the Bible and a more modern event seem to reflect each other very well but believers only accept one as the "true" will of God.
The Islamic State in Iraq and Syria is a self-proclaimed caliphate (a religious state headed by a caliph) whose goal is to unite rule over Muslims all over the world, and in the process rule the world and cover it with sharia law. They commit terrible crimes in the name of Allah. The force women into torturous marriages with their fighters. They've tortured and killed so many people for various reasons which violate their faith.
Are you seeing a pattern yet?
The truth hurts and the truth is that when ISIS burned that Jordanian pilot alive, it wasn't anything the Bible had not done 1000 times over in the name of God.
Religious wars are wars where imaginary leaders call the shots, and whomever thinks they have been chosen by this imaginary leader and is crazy enough to "hear" their voice and can convince others of the same, is a very, very dangerous person indeed.
This is why so many in the nonreligious community view all religion as bad. It can lead otherwise good people to do the worst things imaginable because their faith tells them it is right.

When doing research for this post, this was a top google link on ISIS and I loved it.