At the beginning of Acts 12, we find a seemingly all-powerful Herod wreaking havoc on the church. He had on his side the power of government, the sword, and the threat of prison. But the church had on their side the Creator of the universe and the secret weapon He had given to them, and to us, called prayer.
As Acts 12 comes to a close, we find the great Herod giving a speech. The Jewish historian Josephus points out that at this particular event, Herod was dressed from head to toe in silver. As the sun reflected off him, he looked like a god to the people. At the conclusion of his speech, the people were so taken with him that they began to shout, "The voice of a god and not of a man!" (verse 22). Meanwhile, Herod soaked it all in. So next we read that "immediately an angel of the Lord struck him, because he did not give glory to God. And he was eaten by worms and died" (verse 23). The Lord dealt a fatal blow to a wicked man. The narrative concludes with, "But the word of God grew and multiplied" (verse 24).
So Acts 12 opens with Herod on a rampage, arresting and persecuting church leaders. James is dead, Peter is in prison, and Herod appears to be triumphing. But the chapter closes with Herod himself being struck down, Peter free, and the Word of God triumphing.
If you are a follower of Jesus Christ, then you have access to God through a relationship with Him. You can call on the Almighty God who will hear—and answer—your prayers according to His will.
So you see, it's not over until it's over. That is why we need to keep praying.