Be ye therefore perfect, even as your Father which is in heaven is perfect.
— Matthew 5:48
I’m about to argue that one cannot be a Christian and a Kantian at the same time. Before I do that, we’ll need some definitions: First, as deontology, or duty-based ethics, is a broad field, I’ll limit it to Kantian deontology, as set forth in the Metaphysics of Morals. Second, Christianity will be defined as belief in Yawheh; the deific nature, atonement, and resurrection of Jesus; and a general belief in the truth of the Old and New Testaments. Now on to the argument.
1. The Christian God does not act immorally; he is morally perfect.
2. The morally perfect Christian God performed the Atonement of Jesus Christ.
3. The Atonement of Jesus Christ is immoral under a Kantian framework.
4. Thus, Christians may not be Kantians and maintain rational consistency.
Premise one: The Christian God does not act immorally.
As shown in the opening quote, the Bible frequently repeats that God is perfect, and it supplicates God’s followers to strive to be perfect like him (Deuteronomy 18:13 is another good example, though it is ironic, considering the atrocities committed by God in that same book). Furthermore, moral perfection is one of the defining aspects of the concept of God; if God is not morally perfect, then why call him God? Why not just an advanced human? An omniscient being would necessarily know all things, including the nature of morality, and an omnibenevolent being would necessarily follow the nature of morality.
Premise two: The morally perfect Christian God performed the Atonement of Jesus Christ.
This is not very controversial, though it gets slightly strange if you are trinitarian, considering the whole ‘God sacrificing himself and then praying to himself on the cross’ deal. The only controversy may arise around how exactly God went around performing it; was it God who did it, or was it Jesus for the sake of God, or was it Jesus’ singular choice? And how much choice, exactly, did Jesus have? He was most certainly coerced, after all, by the fact that everyone’s souls would be set on fire if he didn’t atone for them. Like the coward that I am, I’ll avoid these questions by simply saying that God caused the Atonement to happen by integrating it into his plan. Again, there is the question of how much choice God had in creating the plan, but regardless, he created the plan, and that inevitably led to the Atonement.
Premise three: The Atonement of Jesus Christ is deontologically immoral.
It is quite clear that Kantian deontology would rule the Atonement immoral. The Atonement distinctly violates the primary principle of Kantianism: we should never act in such a way that we treat others as a mere means to an end. It is using Christ as a mere means to an end, primarily as an instrument for the benefit of the vast majority. I do not mean ‘mere’ as a derogatory term, but rather as a philosophical condition: mere as in ‘little more than as specified.’ The Atonement, after all, was not a mere act, but a pivotal point in Christian theology. However, it is almost universally recognized that Christ was never an end, but that he was always a means. After all, he was called the Lamb for a reason: he was a sacrifice for the sake of others. He offered all of his glory unto his father. This is the type of ‘sacrifice of the minority for the majority’ situation that Kantians condemn. Christ went through horrific tortures, suffering the pain of literally everyone, so that the sins of humanity could be erased. This is permissible under a teleological moral framework, where the means can be justified by its ends, but abhorrent under a deontological, and especially Kantian, moral framework.
Conclusion: Christians may not be Kantians and maintain rational consistency.
One who believes in a morally perfect God must also model his/her morality around this God. Any action that this God performs is necessarily good, and so mortals cannot deny the morality of the action and must, instead, agree with it. It would be irrational and contradictory to say that a morally perfect God did something immoral. If the Atonement is immoral under a Kantian framework, then either God is morally imperfect, the Kantian framework is false, or God does not exist. Only one of these options allows one to retain their status as a Christian, which I defined as one who believes in a morally perfect God, among other things. The other option is to believe that Kantianism is false.
1. God and humans have different moral standards. It is justified for God to kill, but it is not justified for humans to do so. It is justified for God to bystand in the face of suffering, but it is not justified for humans to do so. Thus, we do not have to base our morality on God’s.
2. Kant’s morality is only for autonomous wills (Stanford), and God did not have any choice in the Atonement. It was a necessary aspect of the universe. Thus, he was not an autonomous will, and he was not making the sort of act that Kantianism applies to.
Deuteronomy 18:13 – Thou shalt be perfect with the Lord thy God.
Kant’s Moral Philosophy. The Stanford Encyclopedia of Philosophy. First published in 2004; substantive revision in 2008.