"Smite me, almighty smiter!" These words, sadly, are not limited to Jim Carrey's character in the comedy film "Bruce Almighty". They were also used by an atheist I debated many years ago, when he of course mentioned the age old cliche of the Crusades. But like basically every atheist who has ever used the Crusades as an argument against Christianity, this atheist understood neither Christianity, nor the Crusades.
The first key to responding to the argument from the Crusades is that actually, more often than not, you have no argument to respond to. There are, of course, many exceptions, but 9 times out of 10, the argument is vague and ambiguous. "Well, what about the Crusades?" To that, one may easily respond with
They haven't said anything! "What about the Crusades?" Well, what about the Crusades? Come on, tell me just one thing about the Crusades that should realistically convince any one human being to reject Christianity?
Now, realistically, we could give a simple defence of the Crusades. In reality, while it can't be denied many Crusaders were, frankly, psychopaths with a tendency towards violence, the Crusades themselves were defensive. Territories that had once been populated by Christians were violently taken over, up to and including the "Holy Land" itself, by Muslims, and so the Crusades were launched in response, in an attempt to re-claim territory from hostile invaders.
But we can afford to simply let that go. See, the Crusades have nothing to do with Christianity. Yes, Jesus gets a mention, as indeed God is quite often an afterthought in human war. But tell me, my atheist friends, when did the Crusades happen?
The answer is between 1096 and 1271. So, they started 1,000 years after the Christian faith was "once for all delivered to the Saints" (Jude 1:3), and ended nearly 800 years ago. So, on the one hand, is it really fair to judge Christianity based on what a few "bad eggs" did 800 years ago? I don't think many atheists want to be judged by what some of their people did even within the last 100 years. The Texas Church shooter was an atheist, he committed his crimes in 2017. Carl Panzram was an atheist and a serial killer, committing his crimes in the early 1900s. Even Jeffrey Dahmer, who eventually became a Christian in prison and repented, actually justified his pre-Christian atrocities with his atheistic philosophy. How many atheists want to be judged by the atrocities of their fellow atheists?
Of course, there is one difference in that atheism naturally allows for such immorality. Atheism, by denying the ultimate moral legislator, denies morality by nature. Atheism is an amoral philosophy. The most monstrous of atheists, even the most despicable human beings, under atheism, are morally equal to the most admirable. Thus, it really makes no sense to judge anyone by anyone, nor even to judge anyone at all.
By contrast, Christianity is, as I have already alluded to, a "fixed" faith. That is, it is no longer available for alteration. What Christianity was in the first century, up to and including its policy of "If it is possible, as much as depends on you, live peaceably with all men" (Romans 12:18), and even "...love your enemies, bless those who curse you,do good to those who hate you, and pray for those who spitefully use you and persecute you" (Matthew 5:44), it still was in 1000 - 1300 A.D., and it still remains to this very day.
What that means is that any argument that could not apply to Christianity by 100 A.D. cannot apply to Christianity today. The Crusades did not happen until the early 1000s. Now, in an atheist's mind, was Christianity true before the Crusades? Obviously, they'll say no. So bring an argument that would apply before the Crusades! Christianity didn't suddenly become false because of a turf war between Medieval brutes who just happened to give lip service to a particular religion they weren't even behaving consistently with.
The reality is, Christianity is not based on war, or the lack thereof. It all comes down to one particular moment in history. If Jesus did not rise from the dead, Christianity is false. If Jesus rose from the dead, Christianity is true. Since Jesus did not silently slink back into His tomb when a few nutjobs swung their swords in the wrong direction, the Christian faith is completely and utterly unaffected by the Crusades. No history following the first century is even remotely relevant to the accuracy of the Christian faith, and until the end times, when God finishes up His promises, it never will.