we keep talking about Hindu disunity, but does look like there is Christian disunity in the world as well.
It has always been so lol.
Based on small theological matters( but mainly and realistically because of oogah and boogah ) early on many Churches split, Armenians, Coptics( Egyptians basically, of the Pyramid variety), Ethiopians, Syriacs( spiritual forefathers of the Malankara Church in Kerala ) etc.
Then there was the "Big One", the East-West Schism of 1054, which split the Church into the Catholic( Roman ) and Orthodox ( Greek ).
Overtime Roman Catholic Church converted Germanic tribals, certain Slav tribes(Polish, Croatian) and the vulgar roman speakers( French, Spanish, Italian ) also Berbers of Maghreb, but they became Muslim later because of the caliphate.
The Eastern Orthodox meanwhile converted the Georgians, lots of Slav tribes, the biggest being the Russian-Ukrainian-Belarus grouping, but proceeded to lose most of it's believers to Islam first because of the Caliphate, and then due to Turkish conquest slowly.
Later the RCC had a bout of heresy, also called (((Protestantism))) today thanks to some fat Anglo king wanting to marry many times, shamelessly, and later the Germanics and Nordics also joining in.
Later thanks to European religious and tribal boogaloo wars, Euros started migrating to this land of milk and honey called America, there they again split into over 9000 protestant cults.
There are many incidents of Christian unity vs Islam, mainly regarding the Ottoman Turkis, mostly managed by the Pope being a diplomat between various kingdoms, the Spanish, Portuges, Austrian Habsburg dynasty, assorted German HRE kingdoms, various Italian city state, the Pope's own Papal States, and at times the Russians also.
Specific landmark battles include both the Sieges of Vienna, the Battle of Lepanto, aside from which there were many campaigns by the Spanish/Portuges vs the Ottomans, the Russo-Ottoman wars, the Habsburg-Austrian and Ottoman wars, etc.
In todays secular liberal world, Christianity is a thing of the past in Europistan.
Perhaps that is why they are receiving Mohammed's sword?
Liberalism/Leftist/Marxism is truly the AIDS of Nations