"We feel in ourselves the entire strength of our Christian love which unites us across all borders".
(to the Catholic youth of Bonn,I. 1923)

On his father's appointment in 1920 as ambassador to Germany, he set off for Berlin; a substantial change in the life of the family but not in that of Pier Giorgio. Every day he left the embassy to seek out the poor. He was helped in his wanderings by father Karl Sonnenschein, who was the St. Francis of Berlin. With him Pier Giorgio became the other "ambassador", the most faithful friend of the needy Italians and Germans.

"No human being should be abandoned, whatever his race or religion: charity should overcome all barriers".

To the catholic youth of Bonn:
In these tragic and painful moments when your country is tramples by foreign feet, while your adversary is occupying your homes as an enemy of your country, we Catholic students send you this expression of our fraternal love. We have no possibility of changing the sad situation, but we feel in ourselves the entire strength (whole force) of our Christian love which (unites us)makes us brothers beyond national boundaries.(...)
Modern society is sinking into the sorrow of human passions and is withdrawing from any ideal of love and peace. Catholics, you and we must bear the breath of goodness which can only arise from faith in Christ.(...)
Since peace cannot return to the world without God, you at least men of good faith, keep Him in your hearts who was announced by angels in the cave to be the Saviour of humanity".

He was aware of sharing the life and destiny of the Church. We see him sending alms to the poor of Berlin, writing to friends in the Netherlands asking them to alleviate the misery in Austria; the French occupation of the Ruhr, the most Catholic part of Germany, aroused his ire and he conveyed this in a letter he sent to the Catholic students of Bonn.

"I would have liked to have done a lot for Germans, but unfortunately I can do nothing. Please take this money for the poor children in Berlin: it's not a lot , but it's better than nothing". (to W: Leitgebel,3.XI. 1923)

"In Vienna today there are many homeless women and children who are prey to hunger and misery. My friend has asked me to help them by taking up a collection. In the spirit of the Pax Romana I thought that you could do the same in the Netherlands. (to Maria Schwan)

In 1921 we see him at Ravenna, with such enthusiasm helping to organise the first congress of Pax Romana, an association which has as its purpose the unifying of all the Catholic students throughout the world; he was convinced that it was up to Catholics of all nations to co-operate in the building of the peace of the world.