The great missiologist Paul Hiebert thought of this first and taught me it. He even wrote a paper on it. 1 So I’m just reproducing his ideas really.
Theologians do get into a pickle when trying to describe conversion, the way by which a person turns to Christ.
They get even more confused when they try to apply their theories to people who are other than sentient adults – unborn babies, children, those with severe learning difficulties, for example.
As Paul Hiebert pointed out, an understanding of set theory could help.
A ‘set’ is a collection of things: a tea-set, for example, is a collection of things you need to serve tea.
The set of all Christians
What does the ‘set’ of all Christians look like? Your average theologian will probably reach for the ‘bounded’ set, which means:
Everything that is within these walls (that I define) is in the set. And everything outside the walls, isn’t.
How do you define the walls? Here are some ideas:
- All the baptized
- All who profess faith
- All who (as I was once asked on the streets in Cambridge when I claimed to be already a Christian) ‘have been baptized as an adult and baptized in the Spirit and speaking in tongues as an initial evidence’ (I won’t say whether I passed or not).
The problem is that none of the walls work when faced with the Biblical evidences of God’s grace.
This may be because the ‘set’ of the Christians is not a bounded set.
The centred set
Let’s suggest another type of set: the ‘centred set’. Members of the set are not defined by the boundaries around them, but by their relationship to the centre, which is Christ. If you’re heading toward to the centre, you’re in the set.
If not, you’re not.
This means:
- People a very long way away, but following a sniff of grace are in the set.
- People who look really near (like the religious) but are not oriented to the centre at all, are not in the set.
This (it seems to me) fits much better with the Biblical data. I leave proving this as an ‘exercise for the reader’.
I talked about some of this in my book More than Bananas, which you are invited to download for free from Internet bookshops: