Interestingly, Saul's name change is announced in Acts 13:1-13. It is significant because the name Saul is used 26 times prior and the name Paul is used 126 times after. Saul is only used in regards to his previous life which is a very strong indicator that it happened no later than when his name change is announced.
Also, after Barnabas found him, he took him from Tarsus to Antioch where they continued to teach. Of course, up to this point in the text nothing really stands out as a benchmark. Sadly, the text just does not flat out say when and where it happened. But, it just seems to me that this is most likely where it happened somewhere between the time that he was sent out in Acts 9:30 which happened shortly after his visit to Jerusalem which happened three years after his escape in Acts 9:25. So, Acts 13:9 is the benchmark in my humble opinion.
Time wise, this is 10 to 12 years after Pentecost. Les Feldick says, "They were first called Christians at Antioch because these are Gentiles who are being saved by Paul's beautiful message of God's Grace." However, I might add, Paul preached the Gospel of Grace to Jew and Gentile alike at some point and that is where his problems began in earnest. After all, who cared what the Gentiles believed, they were always viewed as pagans. Some will point to Acts13:4-12 as a type of Israel blindness in that a Jew tried to lead a Gentile from the faith (Rom 11:15, Rom 11:25).
VERSES 27-30: And in these days came prophets from Jerusalem unto Antioch. (28) And there stood up one of them named Agabus, and signified by the Spirit that there should be great dearth throughout all the world: which came to pass in the days of Claudius Caesar. (29) Then the disciples, every man according to his ability, determined to send relief unto the brethren which dwelt in Judaea: (30) Which also they did, and sent it to the elders by the hands of Barnabas and Saul. Here we find the church in Antioch which was predominately Gentile sending money to the all Jewish church in Jerusalem because of their actions in Acts 4:33-35.
As we finish chapter 11, we have seen the stoning of Stephen in chapter 8, were introduced to Saul and his conversion in chapter 9. He shortly thereafter ended up three years in Arabia after they tried to kill him during which time, or shortly thereafter, he received the revelation of the mystery. We have also seen Peter going to Cornelius' house in chapter 10 revelation to him that salvation was also being given to the Gentiles even though he still did not totally understand it. Then the church in Jerusalem sends out Barnabas to find Saul who took him to Antioch where they taught for 18 months and were first called Christians. Now chapter 12 turns back to the happenings in Jerusalem, after which Peter will slowly roll of the scene except for chapter 15 and the Jerusalem Council.
This entire chapter, based upon the death of Herod, occurs in 44 AD. When it refers to Herod the King, it is a reference to Herod Agrippa I who was the grandson of Herod the Great.
VERSES 1-2: Now about that time Herod the king stretched forth his hands to vex certain of the church. (2) And he killed James the brother of John with the sword. Which the exception of Judas who took his own life, this is the death of the first apostle. From now on, the only James referred to is the half-brother of Jesus.
VERSES 3-4: And because he saw it pleased the Jews, he proceeded further to take Peter also. (Then were the days of unleavened bread.) (4) And when he had apprehended him, he put him in prison, and delivered him to four quaternions of soldiers to keep him; intending after Easter to bring him forth to the people. Herod, just like out political leaders today, was trying to appease his base. The days of unleavened bread is a reference to Passover which was a seven day period. Now, many have attempted to make much ado about the would Easter here in this verse by saying that is a pagan reference to the goddess Estarte or Ishtar who was also known as the Mother of Heaven, the mother of Nimrod, Semiramis. However, the word in the Greek is pascha which means Passover. It also comes from the German word oester which means east which points to the rising sun on the day our Lord resurrected from the dead. I see no problem with the word.
VERSES 5-6: Peter therefore was kept in prison: but prayer was made without ceasing of the church unto God for him. (6) And when Herod would have brought him forth, the same night Peter was sleeping between two soldiers, bound with two chains: and the keepers before the door kept the prison. Peter was obviously being guarded for execution.
VERSE 7: And, behold, the angel of the Lord came upon him, and a light shined in the prison: and he smote Peter on the side, and raised him up, saying, Arise up quickly. And his chains fell off from his hands. But God still had a plan for Peter that did not include his death just yet.
VERSES 8-9: And the angel said unto him, Gird thyself, and bind on thy sandals. And so he did. And he saith unto him, Cast thy garment about thee, and follow me. (9) And he went out, and followed him; and wist not that it was true which was done by the angel; but thought he saw a vision. The entire time, Peter thought that he was seeing a vision. Sounds like me before I have had my first cup of coffee.
VERSE 10: When they were past the first and the second ward, they came unto the iron gate that leadeth unto the city; which opened to them of his own accord: and they went out, and passed on through one street; and forthwith the angel departed from him. Again, God still had tremendous plans for Peter. Reminds me of the old saying that we are immortal until God is through with us.
VERSES 11-17: And when Peter was come to himself, he said, Now I know of a surety, that the Lord hath sent his angel, and hath delivered me out of the hand of Herod, and from all the expectation of the people of the Jews. (12) And when he had considered the thing, he came to the house of Mary the mother of John, whose surname was Mark; where many were gathered together praying. (13) And as Peter knocked at the door of the gate, a damsel came to hearken, named Rhoda. (14) And when she knew Peter's voice, she opened not the gate for gladness, but ran in, and told how Peter stood before the gate. (15) And they said unto her, Thou art mad. But she constantly affirmed that it was even so. Then said they, It is his angel. (16) But Peter continued knocking: and when they had opened the door, and saw him, they were astonished. (17) But he, beckoning unto them with the hand to hold their peace, declared unto them how the Lord had brought him out of the prison. And he said, Go shew these things unto James, and to the brethren. And he departed, and went into another place. I am sure that this story was shared and laughed about many times later. Term beckon in v.17 means to use a physical gesture. In this case and others, it seems to be just a waving of the hands to get the audience's attention. Also, notice that it says that they thought that it might be his angel.
Albert Barnes says of this, "This notion arose from the common belief of the Jews that each individual had assigned to him, at birth, a celestial spirit, whose office it was to guard and defend him through life (Matt 18:10; Heb 1:14).
VERSE 18: Now as soon as it was day, there was no small stir among the soldiers, what was become of Peter. The emphasis in this verse is no small stir. These men were going to pay for this with their lives. Interestingly, the same rule should have been applied to the guards who were guarding the tomb of Jesus (Matt 27:62-66; Matt 28:11-15). Any one of the day would have known something was suspicious here because these guards did not lose their lives (Acts 16:25-30).
VERSE 19: And when Herod had sought for him, and found him not, he examined the keepers, and commanded that they should be put to death. And he went down from Judaea to Caesarea, and there abode. Makes you wonder how God would allow these guards to be killed in exchange for the life of Peter. However, we must trust in God's sovereignty.
VERSES 20-23: And Herod was highly displeased with them of Tyre and Sidon: but they came with one accord to him, and, having made Blastus the king's chamberlain their friend, desired peace; because their country was nourished by the king's country. (21) And upon a set day Herod, arrayed in royal apparel, sat upon his throne, and made an oration unto them. (22) And the people gave a shout, saying, It is the voice of a god, and not of a man. (23) And immediately the angel of the Lord smote him, because he gave not God the glory: and he was eaten of worms, and gave up the ghost. Sounds like something right out of a modern-day horror movie. A scientific journal that I read said that he died of a combination of chronic kidney disease and a rare infection that causes gangrene in the genitalia called Fournier's gangrene. They wrote, “The texts that we depend on for a close description of Herod’s last days list several major features of the disease that caused his death – among then, intense itching, painful intestinal problems, breathlessness, convulsions of every limb, and gangrene of the genitalia,” Jan Hirschmann, professor of medicine at the University of Washington, in Seattle.
VERSE 24: But the word of God grew and multiplied. Of course, we can only assume from the text that this word of God was the Kingdom message that they have been sharing since the Gospels.
VERSE 25: And Barnabas and Saul returned from Jerusalem, when they had fulfilled their ministry, and took with them John, whose surname was Mark. This return was to bring the gift that they had collected from the church in Antioch (Acts 11:27-29) thus fulfilling their ministry. Notice that they are also with John Mark.