By far one of the most influential people I have ever heard speak is Pastor Bill Willson of Metro Ministries. He spoke at Belmont Church in Nashville Tennessee where I was then attending. There were three services and after hearing him speak, when I learned that all his messages would be different, I sat through all three. He didn't mince words and I was shocked at what I can only call his hardcore Christianity. It was a wonderful departure from anything I'd seen before, or since, and he was severely challenging to say the least.
After thinking about this man lately I found an interesting YT documentary on his ministry.
News Weakly - 3/25/2017 - *In a World Gone Mad* The Bible argues that what is needed for Christians is "the renewal of your mind" (Rom 12:2) because, apparently, sin rots the brain (...