We can be the same about the Church. Sometimes we use it the wrong way because we don't really know what it is or what it's for. And, just as in the case of Koto San's grandmother and her use of the Bible, God can, and often does, intervene to bring good results. But, God has revealed in His Word what the Church is and what it's for, and so we shouldn't allow His gracious intervention in our mistakes to serve as an excuse when we don't pay attention to what He has to say.
The big question is whether the Church is a means or an end. Of course it isn't usually put like that, but that's often what it boils down to.
You see, there are really two main ways that people think of the Church. (I say 'think', but often it's more implicit than explicit.) Either the Church is seen as a voluntary society or it's seen as an ontological reality. What on earth does that mean?
The Church as Voluntary Society: Our work for God
If we see the Church as a voluntary society, then we're looking at it as a group of people who have decided to gather together. They come together to worship and serve God, but essentially it's their decision to join together. Basically they belong to the Church based on their own voluntary decision to join and to stay a member. They are people who have united themselves together for a common cause.
The big problem with such a view of the Church is that it places all the emphasis on what we do. The Church becomes a human work: we bring it together.
Now, of course, we don't want to place the emphasis on human works, but on God's grace, and so seeing the Church in this way means that the Church ends up being a means to an end. If the Church is a human work, then it can't be ultimate. So it's seen as a means to a God-glorifying end.
And so people come to think of the Church as the best means for evangelism or carrying out world missions. They think of the Church as existing in order to facilitate mission. The end goal is seen as the salvation of souls, and the Church is a means to that end.
The Church as Ontological Reality: God's gift of grace
But there is an alternative perspective on the Church. And the alternative perspective isn't simply another option to choose from, but rather, an altogether more biblical perspective on the Church. The Bible, you see, doesn't look at the Church as our work for God; as a group of people who decided to come together to further the work of the gospel. No, the Bible sees the Church in a different light. According to Scripture, the Church is the special object of Christ's love for which He died (Acts 20:28; Eph. 5:25). So it's not just a convenient word for a group of Christians. More than that, the Bible tells us that the Church is the Body of Christ (Eph. 1:22-23; Col. 1:24). The Body of Christ isn't just an image of what the Church is like, but is actually what the Church is. And this Body is united to Christ her heavenly Head by His Holy Spirit. As D.P. Williams wrote, ‘the Body of Christ … is a Divine structure in which the life of Christ indwells.’ (D.P. Williams, ‘The Ministry of the Word’, in The Enduring Word [Penygroes: Apostolic Publications, 1944], 174). The Church is Christ's Body and this Body comes to us as a gift of God's grace. We don't decide to join together and bring about the church; no, God in His grace places us into the Body of Christ. As Christ said, 'I will build my Church' (Matt. 16:18) and it is He who 'add[s] to the church daily those who are being saved' (Acts 2:47). The Church is a gift of God's grace.
And if the Church is God's gracious gift, that means that the Church can be the end rather than the means. You see, it's not simply that the Church can do things that bring glory to God, but the Church in itself brings glory to God (Eph. 3:21). That means that the Church isn't the means to a God-glorifying goal, but the Church is itself the God-glorifying goal, now (Eph. 3:10) and on into the ages to come (Eph. 2:7). In fact, the Church is, with Christ Himself, at the very centre of God's Eternal Purpose (Eph. 3:10-11).
So if a God-glorifying Church is the goal, that means evangelism and missions are the means. The Church doesn't exist for evangelism (although it is important to stress that evangelism is of the very nature of the Church, see Acts 2), rather evangelism exists as the way in which Christ builds His Church. That means conversion isn't the be all and end all, but rather that we are saved in order to be part of the Body of Christ.
So, what is the Church for? It's for fulfilling God's Eternal Purpose and bringing glory to Him throughout the eternal ages. And building His Church is what Christ has promised to do.
Hopefully that makes at least some sense. It's a big subject and needs a bit more unpacking, so I'll have to come back to it again the next few days.