Happening or approaching already in slow motion, which will like gain speed... there will be some separating done between those who really do believe and those for whom it has only been a convenient facade. A lot it has been done already by changing or confusing the accepted definition of "Christian" so that many bearing the label bear little or no resemblance to Jesus, the Christ. Some of those in groups called cults, I believe, will endure better than many the supposedly main stream Christians because they have already had a taste. In the long run probably anyone who really holds fast to the Lord putting Him first no matter what the cost will be targeted. How soon? How bad?
It depends on how soon the men with power believe they can get away with it. This is where I see it running parallel to what occurred in Germany in the early years of Hitler's rule there. He did fear the large established Catholic and Protestant churches in Germany and initially left them alone when he went after the Jews. When he realized few were concerned about Jews and the people had allowed him to get too strong, and the brainwashed children were growing up on his side, eventually anyone who opposed his ways was in danger. The extent of the danger? How many people suffered and died in WWII?
Cannot happen here? Anyone who is able to recognize the creeping worldliness in supposed Christians and their churches knows it is already happening. Trump could not have stopped it, if that were his thought or any of our thoughts, and Biden may not even try... The churches here will do what the churches in Nazi Germany did... hedge and hold back not really believing it until it was too late to stop it.
The few among us, who really love the Lord will feel the pain in their hearts and likely in their flesh as well. Even now many do not believe it. Too much trust in man to fix what only God can fix... if He would!
