Herod professed to be a proselyte of the Jewish faith.
“Now about that time Herod the king stretched forth his hands to vex certain of the church. And he killed James the brother of John with the sword” (Acts 12:1, 2).
“Herod was professedly a proselyte to the Jewish faith, and apparently very zealous in perpetuating the ceremonies of the law. The government of Judea was in his hands, subject to Claudius, the Roman emperor; he also held the position of tetrarch of Galilee. Herod was anxious to obtain the favor of the Jews, hoping thus to make secure his offices and honors. He therefore proceeded to carry out the desires of the Jews in persecuting the church of Christ. He began his work by spoiling the houses and goods of the believers; he then began to imprison the leading ones. He seized upon James and cast him into prison, and there sent an executioner to kill him with a sword, as another Herod had caused the prophet John to be beheaded. He then became bolder, seeing that the Jews were well pleased with his acts, and imprisoned Peter. These cruelties were performed during the sacred occasion of the Passover.” The Story of Redemption, 292.
“It was during the Passover that these cruelties were practiced. While the Jews were celebrating their deliverance from Egypt and pretending great zeal for the law of God, they were at the same time transgressing every principle of that law by persecuting and murdering the believers in Christ.” The Acts of the Apostles, 144.
“The people applauded the act of Herod in causing the death of James, though some of them complained of the private manner in which it was accomplished, maintaining that a public execution would have had the effect to more thoroughly intimidate all believers and sympathizers. Herod therefore held Peter in custody for the purpose of gratifying the Jews by the public spectacle of his death. But it was suggested to the ruler that it would not be safe to bring the veteran apostle out for execution before all the people who were assembled in Jerusalem for the Passover. It was feared that his venerable appearance might excite their pity and respect; they also dreaded lest he should make one of those powerful appeals which had frequently roused the people to investigate the life and character of Jesus Christ, and which they, with all their artifice, were totally unable to controvert. In such case, the Jews apprehended that his release would be demanded at the hands of the king.” The Story of Redemption, 292.