Origin: Greek suffix -ism
Evangelism has 2 different meanings across 1 category:
zealous preaching and advocacy of the gospel
"After his conversion, he spent every weekend engaging in evangelism by knocking on doors to share his faith with neighbors who had never heard it before."
Sharing news of something in order to convince someone to join or otherwise accept it.
"After years of trying to get his neighbors to switch to solar power, Mark finally launched a successful campaign of evangelism that convinced half the street to install panels on their roofs."
The word comes from combining "evangel," meaning gospel, with the suffix "-ism." It originally referred to the practice or system of spreading the gospel.