This is an excellent book. It shows the difference between being a nominal Christian and being a truly regenerated Christian. I don't want to give anything away, so I will just say that this is a must read. No, those who call themselves Christians but whose fruit (or lack of it)/lifestyles show otherwise probably will not be changed by it. Only the Holy Spirit can change people. But, hopefully, they will think and ask God to show them the truth. And for true Christians, hopefully it will make them more aware of the many pseudo-Christians out there and give them a desire to spread the Gospel and tell of Christ's redeeming blood. God Bless.