Religious zealots are often the most hostile to Christ and the gospel

"Therefore, King Agrippa, I was not disobedient to the heavenly vision, but declared first to those in Damascus and in Jerusalem, and throughout all the region of Judea, and then to the Gentiles, that they should repent, turn to God, and do works befitting repentance. For these reasons the Jews seized me in the temple and tried to kill me. Acts 26:19-21

Why would the Jewish religious leaders want to kill Paul for preaching the gospel? Here are two reasons:

The first is political. They had a power base they did not want to lose. As long as they were the ones everyone looked up to, respected, and even feared, they were happy. Christ and the gospel threatened that power base because it would mean that people had direct access to God through Christ, rendering those in power, powerless.

The second is spiritual/religious. If access to God is by faith in Christ and not by keeping the law and religious rituals, the guardians of the law and the administers of the rituals would not only be irrelevant, but wrong! This is why I believe the self-righteously religions will hate God on judgement day. They will be infuriated when they learn that their religion not only failed to help them, it actually hurt them. Why did it hurt them? Because they were trusting their works instead of in Christ!

This is why the religious zealots are often the most hostile to Christ and the gospel—and to Christ’s people who proclaim Him and His gospel.