The first duty of the Pope and all bishops toward their flock is to give moral directions so that all may be directed towards a life of happiness, both here and in the life after. These moral directions must be based on Divine Revelation. While the Popes had done their jobs well, the same cannot be said of many bishops. Many have tried to give moral directions, but the morality of their directives is not Catholic enough. It is a bit shallow: probably rational, philosophical, psychological, sociological...but not Catholic.
The morality of an act is dependent on whether it leads us to beatitude, i.e. happiness, if possible, here on earth, and in the next. There are many ways of saying the same thing in the Catholic Church. We might say an act is moral if it builds Faith, Hope and Charity, or maybe if it is in accordance to the petitions of the Our Father.
When Pope Benedict went to Auschwitz, he put the blame for the Nazi's attempt to exterminate the Jews on their unconscious desire to exterminate the author of happiness, God. They wanted to author their own happiness. This is the eternal battle between the two cities: the city of God and the earthly city. Germany was trying to build an earthly city in defiance of the city of God. They were trying to create happiness for themselves in the midst of the sorrows of this life. They chose the hollow pleasures of this life instead of the hope held out to them by God.
St. Paul, in his way to Damascus, fell down from his horse and heard a voice: "Saul, Saul, why dost thou persecutest Me?" When Paul asked who art thou? The voice answered: "I am Jesus..."
Obviously, he who persecutes good Christians persecute the very person of Christ. And the Nazis killed a lot of Catholics. Killing Edith Stein and Maximilian Kolbe was an attempt to kill God.
But how about the non-Catholics? Well, they still have the image and likeness of God and to kill them is an attempt to kill God. To see Christ in good Christians and to see the image and likeness of God in others needs the theological and infused virtue of faith. So to kill a Christian or anybody for that matter shows the absence of faith.
Anyone in his right reason should know that it is futile to kill God, even without the infused virtue of faith. So why would they want to kill God?
God gave us a conscience by which, whether we like it or not, we know He exists and will reward the good and punish the evil. They were , in fact, silencing the voice of conscience that prods us to do God's will and not our will. They were trying to erase the image and likeness of God in them. And the viciousness of their attempts showed it was not working.
When the Pope made his statement in Auschwitz, the people's reaction to the Pope's statement was 'Why didn't he give a shallower reason?' Because, when the Church makes a moral judgment, it must be based on Divine Revelation and not on human science. And like all revealed truths, to understand them, one would need faith. The extermination of the Jew, or anyone for that matter, is immoral because they have the image and likeness of God. In fact it is for the same reason that we ought to love everyone.
In the battle against abortion, I often meet the argument 'the right to life' of a child as reason why it is immoral. But the fact that that foetus has the image and likeness of God is the better moral reason.
For the Pope to just make mention of 'Nazi Germany' and 'Jews' in his visit would have made his message merely political, or nationalisitic. In his message he went to the depths of Catholic moral theology, the way the Fathers of the Church used to do, but now abandoned by Catholic moralists since the 15th century.
The morality of the Catholic Church may also be based on the will of God versus the will of man. And so when we hear that family planning is immoral, it is because it is an attempt to frustrate the will of God on the primary goal of the marriage privilege and not so much because it violates the child's right to life. It is choosing one's will over God's will. With this moral basis then any attempt to frustrate God's plan is immoral. (And this would include the approved Catholic family-planning method whose goal is to frustrate God's will). When a mother aborts her child, certainly it is not because he is a Jew, but simply because she does not want the child. Unfortunately Hitler did not like the Jews: Man's will versus God's will. Back to the dictatorship of relativism.
The criterion of morality since the time of Christ, through the apostles and up to the middle ages has been: what will bring us true happiness. Today the basis of morality for most is: what is cheaper or what will maximize my enjoyment of the world, my will versus God's will.
Hitler did not only do his own will; he imposed it on Germany and tried to impose it on the whole Europe. The world was defended by England whose religion was founded by a king who, also, wanting to do his own will, separated himself from Rome and tried to impose that religion on England.
Who will save us from those who say "my will be done?" Perhaps the son of a Bavarian policeman who opposed Hitler. (Painting by Leszek Sobocki of Carol Wojtyla symbolizing the Polish people, stripped, first, by the Germans and then by the communists. Note the white papal skull cap).