Jews and Christians are not considered to be "infidels" by Muslims. They are considered (and this is in the Quran), to be Muslims' "brothers and sisters of the Book" (Bible), and they are commanded by their Prophet to treat their brothers and sisters of the book with respect and kindness. The people who are referred to in the Quran as "infidels" are Pagans. The Bible is considered to be a foundational document of the religion of Islam. So the Christians and Jews have nothing to worry about (and I suspect that most Pagans aren't particularly worried, either). People who say otherwise are promoting a lie.