Ken Costa writes: “Dominating the City of London is a magnificent building called the Royal Exchange, where major commercial transactions are carried out. What Christ did for us on the cross was a royal exchange. Exchange is the image of the market place. Financial traders talk about convertible bonds and interest rate swaps, and all of us have paged through Exchange and Mart and understood the concept of bartering goods. Every day we can ask God to take away our guilt, mistakes and failures and exchange them for peace, security and purpose. We enter into trade simply by asking him to take the acts and omissions that cause displeasure to him – our sin. This is as real a transaction as anyone buying, for example, a car: you take your money, you give it to the dealer, and he exchanges it for a vehicle. But there is a difference. We bring nothing. Jesus gives us a trade that we do not deserve, and completes the bargain as if he were on both sides.

Imagine someone going into a bureau de change with a stack of retired currency – French francs or German marks. They would of course be rejected, because they would bring nothing to the trade. French francs cannot be exchanged for US dollars – they are worthless; they ceased to have any value with the creation of the euro. Imagine if someone were prepared to accept the trade. We would think them either astonishingly stupid or amazingly generous. Why would someone exchange valuable assets for worthlessness? But this is precisely what Jesus did on the cross. He entered into the Great Exchange, by which he gave up his riches for our poverty. ‘For you know the grace of our Lord Jesus Christ, that though he was rich, yet for your sakes he became poor, so that you through his poverty might become rich’ (2 Corinthians 8:9). This is a compelling verse: riches for poverty; life for death, freedom from guilt.”

Ken Costa, God At Work, 2013, London: Alpha International, p.127-128