The zeal of the convert is a term describing particularly fervent devotion to new beliefs at variance to one's old beliefs.
For example, Paul the Apostle, formerly known as Saul of Tarsus, was a Jewish Pharisee who persecuted Christians until he had a life changing vision on the road to Damascus and became a missionary who spent his life spreading the religion throughout the Roman empire and was executed in Rome for his beliefs. As a more recent example, in the United Kingdom, less than 4% of Muslims are converts, while 12% of domestic jihadists are converts. 69% of converts claim that religion is vital to them, compared to 62% of non-converts. 51% of converts worship at least once a week, compared to 44% of non-converts. 82% of converts claim an absolute belief in God, compared to 77% non-converts.
