I'm still gnawing away at this 'redeeming culture' notion. In part it's a semantics issue but underlying the semantics is an important matter - what is the church's responsibility to society and what can it hope to achieve.
The Kuyperians (not a Star Trek race but followers of A. Kuyper a dutch calvinist) believe the task of the church is to transform the structures of society and through this advance the Kingdom of God cosmically. Some use language about 'redeeming' culture.
I have big problems with this. The first is a singular lack of emphasis on such a mission in Scripture. We read the epistles in vain for Christians to renew, redeem or rescue culture. Redemption in the 'already' of the Kingdom is emphatically of individuals. It is the church who are described as 'the redeemed' and no one (and nothing) else. In fact they are described as 'redeemed from the earth' (Rev 14:3).
Even for believers redemption is presently partial. For example, they await the 'redemption of the body'.
There is to be sure a 'day of redemption' still to come. It is a reference to the consummation of the Kingdom when God's people will be fully rescued from all that oppresses and the creation itself will be 'set free' from its bondage to corruption (Roms 8:21). However, Scripture carefully distinguishes between God's liberating of creation and his judging of culture.
Human culture in a fallen world is, in Scripture, the world in opposition to God. It cannot be redeemed nor does Scripture give any encouragement to try to redeem it. God does not intend to redeem it but judge it; it is Babylon that will 'fall in one day' (Rev 17,18). The best that Christians can do for culture is a kind of 'law-work'. Indeed, a law-work is all that God himself does. In common grace God institutes structures and authorities to limit evil and punish wrongdoing (Roms 13). Christians, acting as salt, can be part of this law-work. They can work for fairer structures in society and be involved in humanitarian causes. But these, we should never forget, are bandages not a cure.
We should never confuse these with 'redeeming society'. In fact what they do, with greater or lesser insight and effectiveness non-Christians do to and non-Christians are certainly not redeeming society.
God is not redeeming society or culture or the world. He is redeeming a people 'out of the world', 'ransomed from every tribe and tongue and people and nation' (Rev 5), to be his chosen 'peculiar' people, and he does so by the gospel.
It is important to use biblical concepts carefully. When we get too loose and cavalier we end up with a skewed theology and a church with a skewed agenda. It is not our job to christianize culture. Nor is there such things as a Christian economics policy; a Christian political policy; a Christian Social policy. There is only Christians active in culture seeking to stem evil and promote good according to their sanctified abilities.
Sometimes the myth is sold that if only Christians forgot doctrine and concentrated their energies on societal reform they would be united. But it is a myth. For, in practice, when Christians try to agree such policies they end up in much greater disagreement than they even do over matters of the gospel. The reason is simple; the Bible tells us what the gospel is (which at least limits disagreement) but it says nothing about political, economic or social theory at all (therefore grounds for difference are boundless).
Let biblical words bear their proper biblical weight and intention. God is presently redeeming for himself a people out of the world; he is not redeeming culture. Let the church preach the gospel of redemption and let redeemed Christians not forget as they evangelize to 'do good to all men, especially those of the household of faith'.