Act 13:44-48 And the next sabbath day came almost the whole city together to hear the word of God. But when the Jews saw the multitudes, they were filled with envy, and spake against those things which were spoken by Paul, contradicting and blaspheming. Then Paul and Barnabas waxed bold, and said, It was necessary that the word of God should first have been spoken to you: but seeing ye put it from you, and judge yourselves unworthy of everlasting life, lo, we turn to the Gentiles. For so hath the Lord commanded us, saying, I have set thee to be a light of the Gentiles, that thou shouldest be for salvation unto the ends of the earth. And when the Gentiles heard this, they were glad, and glorified the word of the Lord: and as many as were ordained to eternal life believed.
As many as were ordained to eternal life - St. Luke does not say fore - ordained. He is not speaking of what was done from eternity, but of what was then done, through the preaching of the Gospel. He is describing that ordination, and that only, which was at the very time of hearing it. During this sermon those believed, says the apostle, to whom God then gave power to believe. It is as if he had said, "They believed, whose hearts the Lord opened;" as he expresses it in a clearly parallel place, speaking of the same kind of ordination, Acts 16:14, &c. It is observable, the original word is not once used in Scripture to express eternal predestination of any kind. The sum is, all those and those only, who were now ordained, now believed. Not that God rejected the rest: it was his will that they also should have been saved: but they thrust salvation from them. Nor were they who then believed constrained to believe. But grace was then first copiously offered them. And they did not thrust it away, so that a great multitude even of Gentiles were converted. In a word, the expression properly implies, a present operation of Divine grace working faith in the hearers. (link)
Calvinists understand the passage as God's predestination from eternity, Arminians understand it as God's prevenient grace in time. Wesley quickly and clearly brings out the three best reasons to favor the Arminian view.
- the original word [tasso] is not once used in Scripture to express eternal predestination of any kind - Tasso would be an unusual word to convey predestination. Προορίζω (proorizo) would be more common. In fact, this would be the only such use of tasso in that sense out of the eight New Testament uses and 65 Old Testament (using the Septuagint) uses. Further, tasso is in the pluperfect, which would be a strange tense for predestination; one would expect something more definitive, like an aorist or perfect tense for predestination.
- He is not speaking of what was done from eternity, but of what was then done, through the preaching of the Gospel. - In Greek, when you join a perfect participle with an imperfect “to be” verb you get a periphrastic pluperfect. In this verse ησαν is an imperfect to be verb and τεταγμενοι is a perfect participle, so we have a pluperfect. The timing for pluperfects are derived from their contexts. The Gentiles were ordained to eternal life when they heared the gospel and received it with gladness. 'Eternity past' isn't in the context and appears as more of an aside, outside the historical narrative, which is a problem for Calvinists since pluperfects derive their timings from narratives.
- Not that God rejected the rest: it was his will that they also should have been saved: but they thrust salvation from them. - Verse 48 and 46 parallel each other. “they were glad, and glorified the word of the Lord: and as many as were devoted to eternal life” from verse 48 corresponds to verses 46 “but seeing ye put it from you, and judge yourselves unworthy of everlasting life”. The Calvinist interpretation is asymmetrical and the Arminian interpretation is symmetrical.
Finally, Wesley anticipates and preempts an objection. What if Calvinists retreated from the position that the passage teaches predestination, but instead said the passage teaches irresistible grace? Does the passage teach God does something before believe that necessitates belief? Wesley replies: Nor were they who then believed constrained to believe. But grace was then first copiously offered them. And they did not thrust it away, so that a great multitude even of Gentiles were converted. In a word, the expression properly implies, a present operation of Divine grace working faith in the hearers. The idea is that although enablement is a core element of prevenient grace, prevenient grace doesn't stop there. Prevenient grace will carry us through conversion, so long as we don't resist. Just before faith, they could still choose to resist, but if they did so they would fall out of the number of those ordained to eternal life. However, if they don't resist, God's grace will see them through (John 6:45, 7:17).