"If I speak in human and angelic tongues but do not have charity, I am a resounding gong or a clashing cymbal. And if I have the gift of prophecy and comprehend all mysteries and all knowledge; if I have all faith so as to move mountains but do not have charity, I am nothing. If I give away everything I own, and if I hand my body over so that I may boast but do not have charity, I gain nothing.
Charity is patient, charity is kind. It is not jealous, is not pompous, it is not inflated, it is not rude, it does not seek its own interests, it is not quick-tempered, it does not brood over injury, it does not rejoice over wrongdoing but rejoices with the truth. It bears all things, believes all things, hopes all things, endures all things.
Charity never fails. If there are prophecies, they will be brought to nothing; if tongues, they will cease; if knowledge, it will be brought to nothing. For we know partially and we prophesy partially, but when the perfect comes, the partial will pass away. When I was a child, I used to talk as a child, think as a child, reason as a child; when I became a man, I put aside childish things. At present we see indistinctly, as in a mirror, but then face to face. At present I know partially; then I shall know fully, as I am fully known. So faith, hope charity remain, these three; but the greatest of these is charity." ~ 1 Corinthians 13
(According to Luciana Frassati, Pier Giorgio always carried this scripture with him. His handwritten copy is pictured here.)