"The Christian Church?" You do know there are thousands, tens of thousands different denominations. Here's a good article:
HOW MANY CHURCHES AND DENOMINATIONS ARE THERE IN AMERICA AND THE WORLD? (continued) - The Complete Pilgrim - Religious Travel Sites
33,000 in America. However, "For true denominations involving multiple churches under common leadership, the number is almost certainly less than two thousand. Major ones, with over a million members, probably less than five hundred."
No doubt Satan is looking to stir and move to the dark side those who have faith in Jesus Christ. That doesn't mean the Churches are influenced by Satan or his demons. They are led by and full of imperfect human beings and will make errors in judgment and administration. But, that doesn't make them demonic in any way. They are all mostly false in their doctrines but that doesn't make the people and the churches evil.
Atheists have pushed so hard that they now are a religion with their own ideology, prophets (Darwin as an example), institutions such as colleges and universities, Priests (Educators at colleges and universities and so on. their moral doctrines change with the wind based on society's ills and elusions.