Oddly, or perhaps not, Christianity grows most when it is in a minority without government support. Look at Rome before Constatine, or modern day China. Not long ago some American pastors met with some Chinese underground pastors and said they would help them with Bibles, ministers, and money for buildings, The pastors said they didn’t want the help, that Christianity was exploding because people had to practice it in their homes, share Bibles, and become their own ministers.
Persecution has a purifying effect, no doubt.