Galatians 1:13-14

You have heard of my career and former manner of life in Judaism, how I used to hunt down and persecute the church of God extensively and [with fanatical zeal] tried [my best] to destroy it. And [you have heard how] I surpassed many of my contemporaries among my countrymen in [my advanced study of the laws of] Judaism, as I was extremely loyal to the traditions of my ancestors.