The context of Acts 13 is about the preaching of the gospel by Paul and Barnabas. It was preached first to the Jews in the Synagogues who rejected the message, and then to the Gentiles who embraced the divine revelation of God. That is precisely the message conveyed by the text of Acts 13:48 in its respective context. Consider the gospel presentation delivered by the Apostle Paul prior to him articulating the statement being addressed in this article:
"Therefore let it be known to you, brethren, that through Him forgiveness of sins is proclaimed to you, and through Him everyone who believes is freed from all things, from which you could not be freed through the Law of Moses. Therefore take heed, so that the thing spoken of in the Prophets may not come upon you:‘Behold, you scoffers, and marvel, and perish; For I am accomplishing a work in your days, A work which you will never believe, though someone should describe it to you.’” (Acts 13:38-41)
He delivered a thought-provoking sermon to the Jews on salvation being given by the Lord to "everyone who believes," thereby demonstrating that choosing to believe is a necessary condition in order for election to take place. Warnings of perishing eternally in the afterlife were uttered to those who were scoffing at the message of the gospel. The people who reject the gospel are under condemnation by God. Faith is the fundamental element in election; the instrumental cause of our justification. Paul and Barnabas went to the Synagogue on the upcoming Sabbath at the request of many Jews, and to their jealously several individuals from Antioch attended (Acts 13:46-48). Verse forty-six is absolutely critical in understanding Acts 13:48:
"Paul and Barnabas spoke out boldly and said, “It was necessary that the word of God be spoken to you first; since you repudiate it and judge yourselves unworthy of eternal life, behold, we are turning to the Gentiles." (Acts 13:46)
The Jews rejected the preaching of Paul and Barnabas. So the two traveled elsewhere to evangelize the Gentiles. That is precisely the meaning of Acts 13:48. That is what the surrounding context of the passage being discussed is about. The Gentiles received the gospel with great joy and readiness of mind through the indwelling of the Holy Spirit. They were glorifying the Lord as a result of Him offering to them the opportunity of salvation. This is about the Gentiles believing after the rejection of the gospel by the Jews. There exists a systematic contrast in the reaction of both groups. This has nothing to do with some predetermined decree. Nevertheless, Calvinists heavily emphasize the word "appointed" in Acts 13:48 in isolation of context to support their doctrine of unconditional election. Consider these observations by Dr. Jack Cottrell on the Greek word for ordained:
"The key lies in the form of the main Greek verb, tassō. The basic meaning of this verb is “to place, to order, to appoint, to ordain, to determine, to arrange in order.” As it appears in this text, the verb form is the participle tetagmenoi. It is simply assumed that this is the PASSIVE form of the verb, thus: “to be appointed, to be ordained, to be destined.” What is often forgotten is that in the Greek language, often the passive and the middle form of verbs are spelled exactly the same way. That is the case here. The word tetagmenoi can also be the MIDDLE form of the verb. Here is the main point: that is how it should be understood in Acts 13:48."
Nowhere does the context mention a divine decree. Nowhere is man's alleged inability to respond to the callings of God implied in this text. Nowhere does Acts 13:48 state that one must be elected in order to believe, or even that all who are chosen will believe. It does not state that faith is a gift of God. Calvinists are simply reading their doctrine of unconditional election into this passage of Scripture. It is not taught there.