What is the effect of repentance upon a person's life?

Gary Powers explains in this video that before the Welsh revival, some of the donkeys that worked at a factory were trained by curse words. After the revival, which led to the conversion of many of the men who worked at the factories, many factories were shut down because the converted men could not use that language around the donkeys. 

Repentance changes all aspects of life. Just as repentance had a wide-ranging economic impact upon a nation, repentance will also affect countless areas of an individual's life. 

2 Corinthians 5:17 (NKJV) – “Therefore, if anyone is in Christ, he is a new creation; old things have passed away; behold, all things have become new.”

I recall one of the stories from the Welsh Revival where the nation was so corrupt that even the factories, they had the donkeys that were running some of the, pulling some of the equipment, were trained by swear words, curse words. And it shut down some of the factories because as the men were converted in the revival, They could no longer use that kind of language. And so they had to retrain the animals. That's a very small microcosm of a nation that repents and reforms. It would change every system, government, education.