"We know that all things work together for good for those who love God, who are called according to his purpose." Romans 8:28 (NRSV, italics mine)
This familiar verse has an interesting and largely neglected history of interpretation. A couple of points are worth noting. First, the Greek word translated as "purpose" is prothesis. Interestingly, it can also be taken to mean "choice." Second, the possessive pronoun which I have italicized and which, to my knowledge, shows up in all English translations, is not in the Greek text. Paul did not explicitly state that the prothesis, whether it means purpose or choice, is something here belonging to God. So, this verse could be legitimately translated, "Now we know that to those who love God, all things work together for good, to those being called according to choice."
Fourth century preacher, theologian, and Archbishop of Constantinople John Chrysostom took this verse to be referring to the prothesis of those who love God, namely human beings who respond to God's call. In his homily on Rom 8:28 he said,
The prothesis he here mentions, however, that he might not ascribe everything to the calling; since in this way both Greeks and Jews would be sure to cavil. For if the calling alone were sufficient, how came it that all were not saved? Hence he says, that it is not the calling alone, but the prothesis of those called too, that works the salvation. For the calling was not forced upon them, nor compulsory. All then were called, but all did not obey the call (NPNF, 1st series, 11:453).
I have maintained the original Greek prothesis in this quote because the translator did not agree with Chrysostom's reading that the purpose/choice is that of the called rather than that of the caller. That Chrysostom saw the prothesis as being on the part of the called may indicate that he took it to mean "choice." The point here is simply that Paul's language is unclear as to whether the purpose/choice in question is that of God or that of those whom God calls. Chrysostom takes it as the human response enabled by God's initial call. This is a clear and ancient denial of the Calvinist idea of an effectual call. This is important because it demonstrates that the Arminian affirmation of resistible grace is not innovative. Rather, it recaptures a strain of thought present in the ancient church and held by none less than an Archbishop of Constantinople and one of the most influential and respected of the early Greek fathers.
**I am thankful to Dr. Ben Witherington of Asbury Theological Seminary for first drawing my attention to Chrysostom's reading of this verse.