In the rather small medieval communities of Austria, everyday contact between Jews and their Christians neighbors was a matter of course: Jews lived in the houses of Christians, or visited them and drank from their glasses, thus showing mutual trust and respect. Rabbi Jacob Molin states for himself and his fellow Rabbi Aaron Bluemlein with whom he attended the Viennese Yeshiva that he stayed in the houses of Christians and drank from their glasses (Minhagei Maharil, 163, and THD nr. 239 - Jewish religious customs), but Rabbi Isserlein used his own dishes during his travels.
Christians participated in the family holidays of their Jewish neighbors and delivered them food. On Jewish holidays, especially on the second day, Christians brought their Jewish neighbors bread, fresh eggs and fruits, even live poultry. This gave rise to the halakhic problem whether these presents could be accepted or not (Halachot Uminhagei Maraharasch, nr. 55-7, 471, 476-7, 393; LJ I, 101 – Jewish religious law.) Jews and Christians played cards together; they helped each other in times of fire or attacks, even when this meant that the Shabbat had to be desecrated. Jews participated actively in protecting the places in which they lived. An example from Wiener Neustadt shows that when Jews had to fight an enemy besieging the town in which they were living, all work, usually forbidden on Shabbat, was allowed. A source from the 15th century stresses that Jews participated in building the fortifications to protect the city from danger.
"A city in which Jews live, was once threatened by annihilation and all the inhabitants were much worried that their city could be conquered by an assault or the use of some cunning trick. So the order was given to strengthen its fortifications and to put up guards day and night. Now the authorities also called the Jews to participate to the best of their best abilities in building the fortifications". (THD nr. 345 - Jewish religious customs).
Occasionally, Jews would also use weapons:
"In front of the city appeared suddenly an army of an enemy in order to loot and take cattle as booty. When the citizens took up their arms to defend themselves and save the cattle, Ruben borrowed from Simon a suit of armor and other weapons to support the citizens and stop the enemy". (THD, nr. 328 - Jewish religious customs).
Jewish laws prohibited a too close relationship with Christians: intermarriage and sexual intercourse with non-Jews were forbidden, Jews were to keep dietary laws which made eating together with Christians more difficult and there was the strong prohibition of even indirect participation in what was described as idolatry.
Such conceptions of exclusivity dating from biblical and Talmudic times gave rise to problems in the medieval communities, since only in large communities it was possible to limit or even avoid contact with non-Jews. Realizing this problem, Jewish scholars in the 11th and 12th centuries found ways to relax these strict rules, in order to facilitate business relations between Jews and non-Jews. The prohibition of trade on Christian holidays and places was abolished and the rules for pawnbrokers were relieved. The Shabbat rest also gave rise to conflicts with the Christian population. The mayor of Wiener Neustadt once ordered a Jew to return a pledge to a Christian debtor on Shabbat. Rabbi Isserlein permitted it on condition that the moneylender did not touch the returned money. Jewish moneylenders often gave their Christian customers keys to their cellars and chests to enable debtors to recover their pledges on Shabbat.
Medieval rabbis and sages frequently complained about the laxness of their generation, which shows that there was a certain discrepancy between the strict rules and daily life. Jewish society found itself under pressure to easy its own rules, which proved to be difficult when it wanted to keep its identity. In the High Middle Ages there appears to have been a certain willingness to compromise, but in the Late Middle Ages, reacting to the stronger pressure of Christian society, the Jewish community sealed itself off.
On the Christian part, canon law tried to prevent social contact with Jews as well. In the 13th century some regulations entered secular law, but only in the 15th century did towns start to prosecute some aspects of social relations, such as gambling, common bathing, sexual relationships or the participation in feasts of the other religion.
These frequent mutual prohibitions show that personal and non-formal contacts between members of the two religions existed, and one may wonder how much of these orders were obeyed at all. They clearly show that there was mutual attraction and even much curiosity in the other religion and its customs - knowing that Jews believed that the mezuza at their gates kept demons and evil spirits away, the Archbishop of Salzburg asked to purchase one and had it put up at the gate of his house (Minhage Maril, 593, nr. 4 – religion customs), or at least knowledge of each other’s sensibilities. Rabbi Isserlein reports on a priest to whose garments or hats the sign of the cross was attached; the question was if it is allowed for Jews to pay tribute to them or to raise the hat in front of them, since they might have been suspected of honoring the cross. In his responsa Rabbi Isserlein inserts a recollection from from his childhood:
"In Vienna lived a Prussian priest, a member of the Deutsche Ritterorden (a German crusading military order), who was in charge of the administration of all the Prussian possessions in the city. All priests of this order showed a cross on their robes. Since he knew that Jews who visited him in business matters would not be able to pay reverence to him at the sight of the cross, he had the custom of covering the cross with a fold in the robe whenever he met Jews to make it easier for them to show their respect to him."
In the synagogue of Marburg, which belonged to the duchy of Styria, some places were kept for Christians who visited the synagogue occasionally.
Some religious functions would not have been possible to keep without the help of Christians, for example the shabbes goy who lit the fire and milked the cows on Shabbat. Jews sold their leavened food for a symbolic price to Christians before Pessach. Because of the dietary laws, care was required when non-Jews prepared meals to prevent the risk of food becoming ritually impure. Many rabbis permitted the purchase of butter, cheese and sauerkraut from Christians, although not for the religious festivals.