Many Christians are suspicious of ethics. They think it undermines grace and distracts from the preaching of the gospel. They also fear that it leads to legalism. They want to emphasise, quite rightly, the fact that salvation is a gift that we cannot earn. (1) (2)

Salvation is indeed through God's grace alone and is received by faith alone. This is one of the great biblical truths rediscovered by the Reformers.

The idea of 'substitutionary atonement', that Christ died in our place for our sins and for our justification, is absolutely central to both Old and New Testaments. It underlies the Passover, the Jewish sacrificial system, temple worship and the Day of Atonement and is clearly taught throughout the Prophets, (3) the Gospels (4) and the Epistles. (5)

But I wonder if by misunderstanding 'grace alone' we are in danger of embracing what the German war-time Christian martyr Dietrich Bonhoeffer termed 'cheap grace', 'the deadly enemy of the church'. (6)

'Cheap grace is the grace we bestow on ourselves. Cheap grace is the preaching of forgiveness without requiring repentance, baptism without church discipline, communion without confession... Cheap grace is grace without discipleship, grace without the cross, grace without Jesus Christ, living and incarnate.'

'Cheap grace' results from a lack of understanding of the true nature of repentance and faith, which in turn stems from a failure to appreciate the holiness of God and the seriousness of sin.

Both repentance (7) and faith (8) are themselves gifts of God's grace – he enables us to repent and have faith because we are incapable of doing it on our own.

But repentance is more than saying sorry. It involves an active turning from sin to obedience. We leave our former life behind and follow in Jesus' footsteps. He becomes our Lord and master.

John the Baptist tells his would-be baptism candidates to 'produce fruit in keeping with repentance'. (9) Jesus takes the same approach: to the rich young ruler, 'sell your possessions and give to the poor'; (10) to the healed cripple by the pool of Bethesda, 'stop sinning or something worse will happen to you'; (11) to the woman caught in the act of adultery, 'leave your life of sin'. (12)

To say sorry, and to then continue in sin, is not repentance. It is presumption.

In the same way faith is more than mere belief, mere intellectual assent to a doctrinal checklist. It is trusting obedience. James tells us that even demons believe – and shudder. (13) Demons however, do not possess saving faith. They do not trust and obey. (14)

Of course this does not mean in any sense that we contribute something to our salvation. We are powerless to do anything to save ourselves, but nonetheless the evidence of genuine saving faith is a changed life – actions. James gives us the examples of Abraham and Rahab who demonstrated the genuineness of their faith by what they did. (15)

They were, we are told, 'considered righteous for what they did'. If we were in any doubt, James summarises it for us, 'Faith without deeds is dead'. (16)

The apostle Paul's letters are full of the same principle. His letters are full of ethical instruction.

He commends the Thessalonians for their 'work produced by faith' and their 'labour prompted by love'. (17) He prays that the Colossians will 'bear fruit in every good work'. (18) He tells Titus that Jesus gave himself for us 'to redeem us from all wickedness and to purify for himself a people that are his very own, eager to do what is good'. (19) He tells the Romans that they are called 'to the obedience that comes from faith'. (20)

Galatians speaks of faith 'expressing itself through love' (21) and Ephesians adds that we are 'created in Christ Jesus to do good works, which God prepared in advance for us to do'. (22)

Nowhere is this principle of obedient trust more evident than in the Gospels themselves. Jesus says that to those who call him Lord but do not do his Father's will, he will say 'I never knew you'. (23) The difference between the man who built his house on the sand and the other who built it on the rock, is this: Both heard Jesus' words but only one 'put them into practice'. (24)

Obedience to Christ is of course only possible by God's grace, through the indwelling work of his Holy Spirit, (25) but as Christians we are nonetheless called to obey him. In fact the heart of the great commission, sadly so often distorted into an exhortation merely to evangelise, is to 'make disciples of all nations... teaching them to obey everything I have commanded you'. (26)

As a clear corollary of this teaching we are told that a life without obedience is evidence of non-regeneration. (27)

Christian ethics lie right at the heart of the gospel. And following Jesus – having real faith – means having his attitude, (28) walking in his footsteps (29) and obeying his commands. (30)