Luigi Giussani remarks on the event recounted in John 21 in a striking way:
" 'Yes, Lord, You know I love You.'
"All my human preference is for You, all the preference of my mind, all the preference of my heart; You are the extreme preference of life, the supreme excellence of things. I don’t know, I don’t know how, I don’t know how to say it and I don’t know how it can be but, in spite of all I have done, in spite of all I can still do, I love You.
"This yes is the birth of morality, the first breath of morality in the dry desert of instinct and pure reaction. Morality sinks its roots into this Simon’s yes, and this yes can take root in man’s soil only thanks to a dominant Presence, understood, accepted, embraced, served with all the energy of your heart; only in this way can man become a child again. Without a Presence, there is no moral act, there is no morality."
(Quoted from Luigi Giussani, Generating Traces in the History of the World. Montreal: McGill-Queen's University Press, 2010. See pp. 60-61.)