Myself I recall as a child the habit some elderly Polish Jews had of spitting as they walked by a church while muttering "Sheketz teshaktzienu". Growing up in a tolerant multi-cultural society replete with "holiday pageants" and no open religious persecution it was hard to understand the bitterness that still lingered in them.
That is, until you remember that the general acceptance of Jews into Western - read: Chrisian - society is only a couple of generations old and that before this change in attitude we were a disadvantaged minority suffering from different levels of persecution, often in the name of Chrisianity. Fifty to sixty good years, yes, but stacked up against 1800 years of unremitting hatred, persecutions, pogroms, forced conversions and murder it doesn't amount to much time to cast off the old feelings.
It's also worth remembering that despite this cultural change and our general acceptance in Gentile society, that there are still lots of Chrisian groups out there that see it as their mission to convert us all into good J.C. lovers so that he can supposedly effect his second coming. As anyone involved with Jews For Judaism will tell you, there's lots of money being spent on this effort. Behind lots of smiles is an agenda that is pleasantly hostile to our continued existence as a nation. As Chazal said, kabduhu v'chasduhu at the best of times.
Most importantly we must remember that Chrisianity as a religion is innately opposed to Judaism. For all the talk from the Vatican and elsewhere about us being an "elder brother" religion we must remember a simple piece of logic: If J.C. was the son of God come to abolish the Torah and redeem us from our sins by dying for us, if only he who accepts J.C. as his personal saviour gets into Heaven then we are wrong by persisting in our observance of halacha and our refusal to recognize the legitimacy of his mission.
And if they're wrong, if J.C. was a prominent rabble rouser with messianic delusions, one amongst many in that era, if Saul of Tarsus, y"sh, invented the whole religion after suffering from an epileptic fit on the road to Damascus then it doesn't matter if there's a billion people who believe it, it's still false!
One question cannot have two diametrically opposed answers that are both correct.
This is why I was dismayed with several rabbis who identify themselves as Orthodox released a statement shortly before the holidays claiming an affinity for Chrisianity as well as granting it a measure of truth. The idea of the document is amazing in so many ways but mostly for the groveling nature of its text which I am sure was not intended. As just one example, consider this statement:
Mutual? Really? Perhaps that could be said of the first century or so of Jewish-Chrisian conflict before they took over the Roman Empire but ever since then the hostility has pretty much been one way: them on us. The Crusades, the Inquisition, the pogroms, the Holocaust, all of these were not two way encounters. If there is one side that suffered, one side that needs to be apologized to, one side that can safely sit back and wait for the extended hand of reconciliation, it ain't us!
After all is said and done, our response to both Chrisian and Islam can be summarized in one simple request: Could you just freakin' leave us alone already?! Why do we have to beg for more?