Rather than being substantially Hellenized, Paul (prior to conversion) had been a zealous Torah-centered Jew.
After all See full debate…
This is relevant because devout Jews in the time of the apostles were intolerant towards Christians, generally finding their beliefs to be blasphemous and worthy of violent persecution.1
Acts 8:1-3 — Saul was in hearty agreement with putting him to death. And on that day a great persecution began against the church in Jerusalem, and they were all scattered throughout the regions of Judea and Samaria,....
In Galatians 1:13, 22-23, Paul says he was famously violent in persecuting Christians “beyond measure.”1
Galatians 1:13-14 — For you have heard of my former manner of life in Judaism, how I used to persecute the church of God beyond measure and tried to destroy it; 14 and I was advancing in Judaism beyond many of my contemporaries among my countrymen, being more extremely zealous for my ancestral traditions. …I was still unknown by sight to the churches of Judea which were in Christ; but only, they kept hearing, "He who once persecuted us is now preaching the faith which he once tried to destroy.”
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.
1 Corinthians 15:9-10 -- For I am the least of the apostles, and not fit to be called an apostle, because I persecuted the church of God. 10 But by the grace of God I am what I am, and His grace toward me did not prove vain; but I labored even more than all of them, yet not I, but the grace of God with me.
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.
Philippians 3:5-6 — circumcised the eighth day, of the nation of Israel, of the tribe of Benjamin, a Hebrew of Hebrews; as to the Law, a Pharisee; 6 as to zeal, a persecutor of the church; as to the righteousness which is in the Law, found blameless.
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
1 Tim 1:13 — even though I was formerly a blasphemer and a persecutor and a violent aggressor. Yet I was shown mercy because I acted ignorantly in unbelief;
In Acts 7:58f, Paul says he “heartily” endorsed the execution of Christians like Stephen.1
Acts 7:58-8:1 — “…they began stoning [Stephen]; and the witnesses laid aside their robes at the feet of a young man named Saul [Paul]. 59 They went on stoning Stephen… Saul was in hearty agreement with putting him to death.”
In Acts 9, it says Paul was “still breathing threats and murder against the disciples.”1
Acts 9:1-3 — Now Saul, still breathing threats and murder against the disciples of the Lord, went to the high priest, 2 and asked for letters from him to the synagogues at Damascus, so that if he found any belonging to the Way, both men and women, he might bring them bound to Jerusalem.
In Acts 9 & 26, Paul says Christians widely feared him because of his violence. (cf. Gal 1:13.)
Acts 26:4-5 — “So then, all Jews know my manner of life from my youth up, which from the beginning was spent among my own nation and at Jerusalem; 5 since they have known about me for a long time, if they are willing to testify, that I lived as a Pharisee according to the strictest sect of our religion.
Acts 9:26-27 — “When [Paul] came to Jerusalem, he was trying to associate with the disciples; but they were all afraid of him, not believing that he was a disciple. But Barnabas [introduced Paul…]”
In Acts 22:1-5, Paul says “I persecuted this way to the death, binding and… all the Council of elders can testify”1
Acts 22:1-5 — “‘Brethren and fathers, hear my defense which I now offer to you.’ And when they heard that he was addressing them in the Hebrew dialect, they became even more quiet; and he said, ‘I am a Jew, born in Tarsus of Cilicia, but brought up in this city, educated under Gamaliel, strictly according to the law of our fathers, being zealous for God just as you all are today. ‘I persecuted this Way to the death, binding and putting both men and women into prisons, as also the high priest and all the Council of the elders can testify From them I also received letters to the brethren, and started off for Damascus in order to bring even those who were there to Jerusalem as prisoners to be punished.”
In, Acts 26:9-11 Paul says he voted in Christian deaths, beat them, dragged them to Jerusalem for punishment.1
Acts 26:9-12 — “So then, I thought to myself that I had to do many things hostile to the name of Jesus of Nazareth. 10 And this is just what I did in Jerusalem; not only did I lock up many of the saints in prisons, having received authority from the chief priests, but also when they were being put to death I cast my vote against them. 11 And as I punished them often in all the synagogues, I tried to force them to blaspheme; and being furiously enraged at them, I kept pursuing them even to foreign cities. ‘While so engaged as I was journeying to Damascus with the authority and commission of the chief priests,