Kevin, I don't understand your view that Christianity confronts evil and other faiths do not.  Wasn't Jesus a Jewish rabbi?  Don't his teachings on love of God and neighbor spring directly from the Hebrew Scriptures?  Don't our notions of sacrifice and sin offering come from Judaism?  If you mean that the cross brings to mind the evil of the crucifixion, doesn't the Star of David bring to mind the evil of the Holocaust and other persecutions, as Lynne points out?  We can wear crosses on our lapels or around our necks if we wish, but as Jesus said, people will know we are his disciples by our love for one another.  As far as Christmas cards go, I send some with overtly Christian images to Christian friends, some with more generic peace images to non-Christian friends.  I receive a wide variety of cards, both religious and non-religious, and appreciate all of them.