It is self-evident that nuns physically abusing school kids the way priests sexually abuse altar boys means none of them can believe God exists. Because they know no God would allow them to abuse innocent children in his name the way it seems they’ve always done.
Even so, I commend Pope Francis for the humility inherent in making pilgrimages of penances to beg forgiveness for the systemic sins Catholics have committed. This, especially wearing the institutional shame of the whole world knowing that something is very rotten in the Catholic Church. And, as the proverbial fisher of men, this pope knows better than anyone that this rot is from the head down.