There are a few things that come to mind when one speaks of the Crusades, most of them not so pleasant and certainly not Christ advancing. According to Paul Robinson, there are Three Myths about the Crusades, What They Mean for Christian Witness. The first one is of interest in this thread and that is: “The Crusaders were motivated by land, power, and wealth rather than by religion.” Although these benefits were possibly a result of the Crusades, they were not the motivation for them.
In fact Mr. Robinson says that Pope Urban II called for the Crusade at “The council of Clermont in 1095,” concluding a preaching tour. Urban requested the Crusade to assist Christians in the East to help them fight off the Muslim powers.
Therefore it was kind of Christian initiated, but, maybe not for the advancement of Christ Himself’. Another interesting writer of a three-volume set, still selling a half a century later, called, “The history of the Crusades,” is Sir Steven Runciman.
According to Thomas F. Madden it was Runciman who called the Crusades “a long act of intolerance in the name of God, which is a sin against the Holy Ghost.” This probably because the Crusades – although under the guise of Christianity, were certainly not done in a Holy Ghost kind of way at all. Remember, “Thinkest thou that I cannot now pray to my Father, and he shall presently give me more that twelve legions of angels” Did Pope Urban II say anything about instruction from the Holy Ghost Maybe not.
“For the LORD thy God is a consuming fire, even a jealous God.” His glory cannot be shared by someone who will not give the glory to Him. Remember Herod died because he did not give God the glory. Furthermore, whatever God does cannot be mistaken for something man can take credit for: When David defeated Goliath it was because Jesus was with him and David let Goliath know that he ‘defied’ the Lord of Hosts, and there was no mistaken that Goliath’s defeat through David was because of his faithfulness to God. So the Crusades were man initiated, for whatever reasons, without the unction of the Holy Ghost and therefore unacceptable as an advance for the cause of Christ.