Among the reasons why one would have a “heart of stone,” the Pope said that it can easily happen to someone who has gone through a “painful experience.” The Apostle Thomas, who refused to believe in the Resurrection, was just such an example.
Another reason the Holy Father cited is to be closed in on one’s self. “To make a world in one’s self, closed. In himself, in his community or in his parish, but always closed,” he said.
“And being closed can turn into so many things: pride, sufficiency, to think myself better than others, also vanity, no? There are mirror-men and women, who are closed in on themselves and constantly looking at themselves. These religious narcissists, no? But, they have a hard heart, because they are closed, they are not open. And they look to defend themselves with these walls that they have around them.”
Pope Francis continued his homily explaining another reason for a hardened heart: that of “barricading” one’s self behind the letter of the law. The irony of this, he continued, is that those who seek security within the law end up becoming like a “man or a woman in the cell of a prison behind bars: a security without freedom.”
“The heart, when it is hardened, is not free and if it is not free it is because it does not love: that was how the Apostle John’s First Letter concluded. Perfect love chases away fear. In love there is no fear because fear presumes a punishment and he who fears is not perfect in love. He is not free,” the Pope said.
Concluding his homily, Pope Francis said that the only one who can "teach love and free mankind from this hardened heart is the Holy Spirit.”
“You can do thousands of courses of catechesis, thousands of spiritual courses, thousands of yoga courses, zen and all those things. But all of that will never be capable of giving you the freedom of a son,” he said.
“It is only the Holy Spirit that can move your heart to say ‘Father.'"