Last Wednesday I attended some lectures about the challenges and opportunities of Christian Mission to the Muslim and Hindu communities in this country. It was a useful reminder that Christians should be engaging with these communities, showing friendship and hospitality, listening to what they believe (not just what we think they believe!) and also listening to their fears. For example, I didn't know that the Hindu community currently feel very marginalised: both government and Church are bending over backwards to engage with Muslims (for obvious reasons) but very little is heard about making such Hindus have their say.
However, as with many things Church of England, there was a rather obvious lack of engagement with the main questions:
Do Muslims and Christians worship the same God? The speaker said yes. He mentioned one 'faithful Muslim' who loves going to Taize services - a display of unity despite 'doctrinal differences'. It seemed to be taken for granted that Muslims at least partly honour Jesus by declaring him a prophet.
Is there revelation outside Christ and the Bible? The speaker said yes, in response to a question which insisted we shouldn't ignore books such as the Bhagavad Gita. He mentioned approvingly church services in which there had been three readings: Old Testament, Gospel and Bhagavad Gita, although acknowledging that this would be difficult for some.
Although these main questions were touched on, as the examples show, there was no theological engagement with them.
One of Luther's best contributions to the Church was his distinction between a "Theology of Glory" and a "Theology of the Cross". Put simply, if we hold to a theology of glory we imagine God is rather like we think him to be. We claim to know intuitively what "strength" and "glory" and "power" are, and imagine God to be the most strong, most glorious and most powerful. (See here for a better, but still short, summary.)
Luther, like the apostle Paul (see e.g. 1 Corinthians 1-2), thought differently. Sin has darkened our minds so that we do not think straight. What God is like is not what we think him to be like, but he is as he has revealed himself, and this most clearly at the cross. God's true strength, glory and power are revealed in the weakness, shame and humility of the cross.
In other words: a god without the cross is not the True and Living God. Muslims claim to honour Jesus while denying that he was crucified, but this is to deny all that Jesus stood for. It is in fact to mock and dishonour the true Jesus who came, he said, to give his life as a ransom for many (Mark 10:45). Similarly, while the Bhagavad Gita may contain some nice stuff, it does not reveal Truth because it never takes us to Christ and him crucified.