Rather than being substantially Hellenized, Paul (prior to conversion) had been a zealous Torah-centered Jew.
• …Paul was a notoriously zealous pharisee
• …Paul was raised by torah-centered parents
• …Paul was a higher-ranking Jew
• …Paul was formally trained in Judaism under Gamaliel
• …Paul violently persecuted Christians for God
• …As a Christian, Paul's perspectives remained Jewish
In Galatians 1:13, 22-23, Paul says he was famously violent in persecuting Christians “beyond measure.”1
In 1 Corinthians 15:9-10, Paul very emotionally admits he “persecuted the church of God.”1 This is relevant because Paul was rather adamant about defending his apostleship and authority, so his breakdown and confession here of “not being fit to be called an apostle because I persecuted” makes little sense if Paul did not persecute Christians with intensity.
In Philippians 3:5-6, Paul says he was in “zeal,” “a persecutor of the church.”1 This is relevant because “persecutor” already implied violence, and yet to persecute with “zeal” increases the probability even more.
Martin Hengel: “[porthein] has a very harsh ring and denotes violent action. In Josephus, BJ 4.534, it denotes the burning of the villages and towns of Idumaea by Simon bar Giora and is used synonymously with [lumainesthai] (Acts 8.3: ‘Saul laid waste [elumaineto] to the church...). ‘It implies the idea of physical or moral violence against people.’” [The Pre-Christian Paul (SCM, 1991), 72.]
In 1 Timothy 1:3, Paul says he was “a persecutor and violent aggressor”1
In Acts 7:58f, Paul says he “heartily” endorsed the execution of Christians like Stephen.1
So? Plausibly…
• …Acts misrepresents Paul.2
In Acts 9, it says Paul was “still breathing threats and murder against the disciples.”1
In Acts 9 & 26, Paul says Christians widely feared him because of his violence. (cf. Gal 1:13.)
• …Acts 26:4-5 reports.1
• …Acts 9:26-27 reports.2
In Acts 22:1-5, Paul says “I persecuted this way to the death, binding and… all the Council of elders can testify”1
In, Acts 26:9-11 Paul says he voted in Christian deaths, beat them, dragged them to Jerusalem for punishment.1