DUTIFUL Christians who care about tradition will find, if they attend to the New Testament, how radical this tradition of theirs is. The Church began among people who were hoping for a Messiah, a Christ. The Messiah came, but the manner of his coming and what happened, and the way he refounded the tradition that his followers maintain through the centuries, were all quite unexpected. It would be strange to suppose that God has nothing new in store for his people any more. It is more reverent to trust in a God who may surprise us than to suppose that we have the Almighty taped.

A good deal of Christian loyalty to unchanging tradition looks like an attempt to protect God from being let down by liberals. Some of the anxiety people are feeling about loss of standards is based on a notion that God will be shocked if people allow their moral beliefs to develop and change, as if our Heavenly Father were an Aged Parent who will be upset unless each generation keeps everything going on in the same good old way.

But the Christian gospel is not about things going on in the same old way. God is less timid than human moralists and more inclined to take risks. The Son of God when he came took great risks of being misunderstood, both in his teaching and in his behaviour. What happened was the Cross, when it all went horribly wrong, and the Resurrection, when God gloriously brought good out of evil. That is the characteristic pattern of Christian belief.

So, likewise, the shape of Christian ethics turns out to be more risky than careful conformity to settled moral principles. Christians do God's will by entering into the divine pattern of generous offer and grateful response. The key word is "therefore". "God is like this: therefore we are to be like this." That was the basis of St Paul's teaching to the young churches. Our Lord Jesus Christ "died for us so that . . . we might live with him. Therefore encourage one another and build one another up, just as you are doing" - indeed, one may notice, just as St Paul himself was doing.

Tolerant moralists, who sit lightly to fixed standards, do run the risk of preaching "cheap grace"; but it is more dangerous to preach grudging grace. People quickly pick up the message that God is mean. If they have broken the rules, or even if they have not seen the point of the rules, they are not wanted, and God's Church is not for them. That is a travesty of Christian belief, but persists. Some loyal Christians never see the harm they do by their unimaginative confidence. The people they fail to welcome do not stay and argue: they simply go away, and stop expecting the Church of Christ to have any blessings to offer to them or their families.

An extract from Christian Faith for Handing On by Helen Oppenheimer (Lutterworth Press, £15 (CT Bookshop £13.50); 978-0-71889-350-7).