From Turning the Tide - Ends and Means
The deontologist judges an action right or wrong on the basis of whether it conforms to a set of rules or principles. Immanuel Kant was one of the first advocates of deontological decision-making and in the 1980s Beauchamp and Childress first enunciated four prima facie principles of ethics in health care which have become the basis of most contemporary secular ethical discussion. They are:
The consequentialist on the other hand judges an action by its consequences. John Stuart Mill and Jeremy Bentham are usually associated with this category of decision-making and it would be fair to say that most popular contemporary ethical discussion gives far more weight to consequences of decisions than the principles underlying them.
The Christian obviously will respect the authority of Christ and Bible above Kant and Bentham, but it can legitimately be asked whether Christian ethics are deontological or consequentialist? In fact the Bible has elements of both. Take for example the question 'Is adultery, right?' On the one hand the seventh commandment states you shall not commit adultery' (Ex 20:14). Why not? Because God commanded it and we have a duty to obey God. This is a rule-based or deontological argument. However the writer of Proverbs takes a different approach. 'Think about the consequences of adultery' he says in effect. 'All the shame and disgrace not to mention the fury and rage of a jealous husband to contend with. Is it really worth it for a few moments of pleasure? You'll probably end up destroying your marriage and then what about the children? How can that be right?' (Pr 5:1-14; 6:20-35). This is a consequentialist argument. So the Bible sees rules and consequences as being intimately connected. God is loving, trustworthy and profoundly concerned with the welfare of man. It therefore makes sense to obey his commands since to ignore them is to choose unpleasant consequences.
However, recognising this is not enough. We must also recognise that because God is a far better developer of deontological principles and judger of consequences than we are (Pr 3:5,6) it follows that we should trust his judgment rather than our own. This will mean that even in situations where the consequences of a course of action seem to dictate that we should ignore the rules and trust our own judgment rather than God's, we should nonetheless abide by the rule. This is to recognise the limitations imposed on us simply by virtue of being human and sinful. This is the way of faith and this is what makes Christian ethics so diametrically opposed to secular ethics. It is based on God's revelation rather than human wisdom. God is a far better judge than us of principles of conduct and consequences of action. It follows that we must trust his word and not our own judgment. Scripture is full of examples of this. The great men and women of faith are commended for their faith in obeying God's word despite the perceived consequences (eg. Abraham's sacrifice of Isaac (Gn 22:1-19), Moses' return to Egypt (Ex 3:7-4:31), Daniel's persistence in public prayer (Dan 6:6-10)). Conversely those who exhibited lack of faith were they who chose not to obey and rather trusted their own judgment of consequences (Saul's attack without Samuel (1 Sa 13:1-14), Aaron's golden calf (Ex 32). Perhaps the best example of all is Christ's third temptation. Satan offered him all the kingdoms of the world if he would worship him (Mt 4:8-10). We know that to rule over the kingdoms of the world was Christ's destiny - but the means to it was not through worshipping Satan but through submitting to God on the cross. With God the end never justifies the means. We must do his work his way.