If there is no God, no law-giver, then why should we be equal?
Let us first of all remind ourselves that Martin Luther King was a Baptist pastor. Any account of him which leaves out or diminishes that fact does a terrible disservice to the man because the inspiration for his civil rights campaign came first and foremost from his deep Christian faith.
This week is the 50th anniversary of his magnificent, 'I have a dream speech' delivered in Washington DC in front of the Lincoln Memorial, another man who cannot be understood properly without understanding his Christian faith also.
Read King's speech, listen to his speech, and what you encounter is a religious sermon almost from top to bottom delivered in the mesmeric cadences of the black southern preacher, which is what King was, just like his father before him.
In his speech he tells us that "all men are created equal", that is, created by a creator, which is to say, God.
He tells the crowd that we must "make justice a reality for all of God's children". He talks about the redemptive power of "unearned suffering", a deeply Christian idea.
He ends with the words of the old Negro spiritual (his description): "Free at last! Free at last! Thank God Almighty, we are free at last!"
King was fighting the lasting effects of racism and slavery in America, both of which found a theological and a 'scientific' justification.
Christian racists in effect rejected the doctrine that all men are created equal. They believed that God intended some races to be servant races.
Racism also derived plenty of support from the 'scientific' doctrine of Social Darwinism and the idea that the white man had won the battle to be the 'fittest'.
It took World War II to destroy the respectability of Social Darwinism and its close cousin, eugenics.
Stemming from his belief in God, King also believed in a moral law that was higher than any law man could make.
He made this abundantly clear in his 'Letter from Birmingham Jail' when his critics were asking him, "how can you justify obeying some laws and disobeying others?" He was in prison for civil disobedience.
He answered: "I would be the first to advocate obeying just laws. One has not only a legal but a moral responsibility to obey just laws. Conversely, one has a moral responsibility to disobey unjust laws. I would agree with St Augustine that 'an unjust law is no law at all'".
Then he added the punch line: "Now, what is the difference between the two? How does one determine whether a law is just or unjust? A just law is a man-made code that squares with the moral law or the law of God. An unjust law is a code that is out of harmony with the moral law. To put it in the terms of St Thomas Aquinas: An unjust law is a human law that is not rooted in eternal law and natural law."
Not alone is there hardly a politician in Ireland who would come out with a sentence like that today, there are few enough priests or bishops either, of any Church. They know they would stand accused of 'fundamentalism'.
But if there is no God, then what law can possibly be higher than man-made law? If there is no law-giver above us, then we are the only law-givers.
This notion that the only law is the law of the land led the ostensibly Catholic St Vincent's hospital to say recently that it would implement the new abortion law because it always follows the law.
In other words, for St Vincent's hospital there is no law higher than civil law. Martin Luther King would profoundly disagree with that. As would Abraham Lincoln.
When King said "all men are created equal", he was quoting the American Declaration of Independence, itself effectively a theological as well as a political statement.
But if civil law decides we are not equal and there is no higher law we can appeal to, how can we say it is 'unjust'?
King would say, we can't.
In fact, if there is no God, and we are simply a by-product of blind evolution, then why should we be equal? By what principle do we arrive at such a notion other than that it suits us to believe in it?
Politics is full of human rights talk. However, this presupposes there is some kind of a moral law, higher than the civil law, which the civil law must conform to.
Again, Luther would say there is no higher moral law if there is no God, no ultimate law-giver, no creator of our rights, our 'inalienable' rights as Bunreacht Na hEireann puts it. There are simply the 'rights' that the State chooses to give us.
Martin Luther King's 'dream' speech is rightly celebrated as a great civil rights speech.
But it stems from a deep theological and philosophical vision, one that depends on believing in a creator God and in a moral and natural law which He gave us and against which our laws much be judged.