Actually it was weaponized in the very beginning, christianity was forcefully spread in the beginning. I assume you have heard of the Charlemagne?
He campaigned against the
Saxons to his east,
Christianizing them upon penalty of death and leading to events such as the
Massacre of Verden.
"Unlike his father, Pippin, and uncle, Carloman, Charlemagne expanded the reform Church's programme. The deepening of the spiritual life was later to be seen as central to public policy and royal governance. His reform focused on strengthening the church's power structure, improving clergy's skill and moral quality, standardizing liturgical practices, improvements on the basic tenets of the faith and the
rooting out of paganism."
Christianity was a minority religion during much of the
Roman Empire, and
the early Christians were persecuted during that time. When
Constantine I converted to Christianity, it became the dominant religion in the Roman Empire. Already under the reign of Constantine I, Christian heretics had been persecuted; beginning in the late 4th century, the
ancient pagan religions were also actively suppressed. In the view of many historians, the
Constantinian shift turned Christianity from a persecuted religion into
one capable of persecution and sometimes eager to persecute.[2]There are a number of examples of forced conversion throughout the history of Christianity: during the Roman Empire, in the Middle Ages, inquisitions in Spain and Goa, and campaigns by Russian rulers.
Late Antiquity[
edit]
In 392
Emperor Theodosius I decreed that Christianity was the only legal religion of the Roman Empire and forbade pagan practices:
It is Our will that all the peoples who are ruled by the administration of Our Clemency shall practice that religion which the divine Peter the Apostle transmitted to the Romans.... The rest, whom We adjudge demented and insane, shall sustain the infamy of heretical dogmas, their meeting places shall not receive the name of churches, and they shall be smitten first by divine vengeance and secondly by the retribution of Our own initiative" (
Codex Theodosianus XVI 1.2.).
[3]
Medieval western Europe[
edit]
During the
Saxon Wars,
Charlemagne,
King of the Franks,
forcibly Roman Catholicized the Saxons from their native Germanic paganism by way of warfare, and law upon conquest. Examples are the Massacre of Verden in 782, when Charlemagne reportedly had 4,500 captive Saxons massacred upon rebelling against conversion, and the Capitulatio de partibus Saxoniae, a law imposed on conquered Saxons in 785 that prescribed death to those who refused to convert to Christianity.[5]
Forced conversion that occurred after the seventh century generally took place during riots and massacres carried out by mobs and clergy without support of the rulers. In contrast, royal persecutions of Jews from the late eleventh century onward generally took form of explulsions, with some exceptions, such as conversions of Jews in southern Italy of the 13th century, which were carried out by Dominican Inquisitors but instigated by King Charles II of Naples.
[4]
Jews were forced to convert to Christianity by the Crusaders in Lorraine, on the Lower Rhine, in Bavaria and Bohemia, in Mainz and in Worms.[6]
Pope Innocent III pronounced in 1201 that if one agreed to be baptized to avoid torture and intimidation, one nevertheless could be compelled to outwardly observe Christianity:
"[T]hose who are immersed even though reluctant, do belong to ecclesiastical jurisdiction at least by reason of the sacrament, and might therefore be reasonably compelled to observe the rules of the Christian Faith. It is, to be sure, contrary to the Christian Faith that anyone who is unwilling and wholly opposed to it should be compelled to adopt and observe Christianity. For this reason a valid distinction is made by some between kinds of unwilling ones and kinds of compelled ones. Thus one who is drawn to Christianity by violence, through fear and through torture, and receives the sacrament of Baptism in order to avoid loss, he (like one who comes to Baptism in dissimulation) does receive the impress of Christianity, and may be forced to observe the Christian Faith as one who expressed a conditional willingness though, absolutely speaking, he was unwilling ..."
[7]
Eastern Europe[edit]
Upon converting to Christianity in the 10th century,
Vladimir the Great, the ruler of
Kievan Rus', ordered Kiev's citizens to undergo a mass baptism in the Dnieper river.
[12]
In the 13th century the pagan populations of the
Baltics faced campaigns of forcible conversion by crusading knight corps such as the
Livonian Brothers of the Sword and the
Teutonic Order, which often meant simply dispossessing these populations of their lands and property.
[13][14]
After
Ivan the Terrible's conquest of the
Khanate of Kazan, the Muslim population faced slaughter, expulsion, forced resettlement and conversion to Christianity.
[15]
In the 18th century,
Elizabeth of Russia launched a campaign of forced conversion of Russia's non-Orthodox subjects, including Muslims and Jews.
[16]
Goa inquisition[edit]
Main article:
Goa Inquisition
The Portuguese practised religious persecution in
Goa, India in the 16th and 17th centuries. The natives of Goa, most of them Hindus, were subjected to
severe torture and oppression by the zealous Portuguese rulers and missionaries, and forcibly converted to Christianity.
[17][18][19][20][21][22]
In 1567, the campaign to destroy temples in
Bardez met with success, with 300 Hindu temples destroyed. Prohibition was laid from December 4, 1567 on rituals of Hindu marriages, sacred thread wearing and cremation. All persons above 15 years of age were compelled to listen to Christian preaching, failing which they were punished. In 1583, Hindu temples at
Assolna and
Cuncolim were destroyed byh army action. "The fathers of the Church forbade the Hindus under terrible penalties the use of their own sacred books, and prevented them from all exercise of their religion. They destroyed their temples, and so harassed and interfered with the people that they abandoned the city in large numbers, refusing to remain any longer in a place where they had no liberty, and were liable to imprisonment, torture and death if they worshiped after their own fashion the gods of their fathers", wrote Filippo
Sassetti, who was in India from 1578 to 1588. An order was issued in June 1684 for suppressing the
Konkani language and making it compulsory to speak Portuguese, on pain of severe penalties. All non-Christian cultural symbols and books written in local languages were also ordered to be destroyed.
[23]
That and so much more, Christianity was spread by the sword by your fellow Europeans. Also forced conversions are prohibited in Islam so don't go around saying that Islam was spread by the sword.