Why would anyone think that exterminating Jews would make Christians love them. Why would Hitler associate his politics and policies with Christianity? Why would he think these things would cause Christians to love him?
Why did they love him?
Because christians have an incredibly long and well-documented history of hating and exterminating whole communities of jews. I gave a morbidly long, but hardly complete list of these events back upthread a ways, if you want to track down the specifics.