Have you noticed the frequency in Acts of God taking the initiative? This shouldn't surprise me really, but I confess it still does. It's why our current morning series is called shoved by the Spirit because I like those early followers of Jesus needed a good push from time to time to get on with the task at hand.
In the story of the conversion of Cornelius, Peter's still speaking when the Holy Spirit falls on the assembled company. In fact when Peter is reporting this to the leaders in Jerusalem, he says, 'as I began to speak, the Holy spirit came on them.' As a result of the Spirit's action, peter had no choice but to accept these Gentiles into the church.
It's the same at Antioch - people (probably Hellenistic Jews converted on the day of Pentecost, part of the group influenced by Stephen) shared the gospel with Gentiles and they believed. When Barnabas arrived possibly with instructions to calm the excesses, he sees the grace of God at work and gets stuck in (11:23).
So when we get to Acts 15 and the gathering in Jerusalem, experience tells them that the Gentiles are coming into God's people because they are responding to the Gospel and the Holy Spirit is bringing them alive entirely separately from the cultural boundary markers that have distinguished God's people from everyone else for a thousand years.
It was a momentous change
I can't help thinking that we facing a pretty momentous change at the moment - certainly in the relationship of the church to western culture. Christendom is decaying rapidly. The church is an increasingly marginal presence in our culture, jockeying for a place with a load of other beliefs and philosophies all clamouring for the attention of an increasingly apathetic populace.
Where's God? What's the Spirit up to? Which conversation is he going to rudely interrupt by falling on everyone in the room/pub/cafe/cinema/street corner/shop/whatever?
The other awkward issue for a baptist about Acts 15 is that it's the leaders of the church who gather to thrash out the response to this new situation they find themselves in. 15:2, 4, 6, 13, 22, 23 indicate that it's apostles and elders discerning God's leading and communicating that to the church. I guess it would be unrealistic to gather everyone together - you'd never find a time they could all make, not everyone would feel able to speak, not everyone who wanted to speak would get a hearing.
So, I guess this is a good model for us. Have the leaders thrash things out and then communicate it to the rest of the congregation. there's a hint in 15:22 that the decision was owned by the whole church in Jerusalem as they seem to endorse the sending of the letter and then the church at Antioch were over the moon at the outcome (15:31). It's interesting that we think of this as a council of the whole church but in fact it was a dispute between Jerusalem and Antioch - though as Paul's letter to the Galatians (written, I think, just before Paul sets off to the meeting - see my Crossway Bible Guide for justification of this) it affected every church that Paul planted.