VATICAN CITY — Saying Mass for some 500 Italian parliamentarians Thursday, Pope Francis warned them of the corruption of the heart, imploring them not to slip from the theology of faith to a theology of duty.

Describing the religious leaders whom Christ encountered, Pope Francis said March 27, “they resisted the salvation of the Lord’s love and thus slipped away from the faith, from a theology of faith to a theology of duty.”

Because of the large number of parliamentarians who had asked to participate in a daily Mass with him, Pope Francis said Mass for them in St. Peter’s Basilica rather than in the Domus Sanctae Marthae Chapel. Roughly half of Italy’s parliament attended the Mass.

Pope Francis described the readings from the day as “a dialogue between the lamentations of God and the justifications of men.” The first reading gave voice to the “lamentation of God” toward a generation that did not welcome God’s messengers and at the same time justified itself despite its sins.

The “pain of the Lord” is caused by those who “turned their back” on him, and this can be seen also in the reading of the Gospel, which recounted the blindness to God of the spiritual leaders of Jesus’ time, Pope Francis said.

“God’s lamentation comes from the fact that God had done much, much work to remove idolatry from the hearts of his people and to make them docile to his word. He did this for centuries and centuries, until the advent of Jesus.”

And when Jesus came, he recounted, some called him a great prophet, and some a servant of demons, and “God’s people was alone, while the ruling classes — the doctors of the law, the Sadducees, the Pharisees — were closed into their ideas … their ideology.”

Pope Francis said that at Jesus’ time, the ruling class “had become so hardened in their sin that they were corrupt. … They could not hear the call, since they were so closed, so far away from the people.”

Jesus watched the people of God and was moved by them, since they were “sheep without a shepherd,” and so he “went to the poor, to the sick, to everyone, to the widows, to those affected with leprosy: to heal them. And he spoke to all of them with such authority that people admired him,” Pope Francis recounted.

“All of us who are here are sinners,” Pope Francis said. But the corrupt were “more than sinners,” because “it was impossible for them to listen to the Lord’s voice.”

“It is very hard for a corrupt person to turn back. The sinner can, yes, because the Lord is merciful and awaits us all. But the corrupt are fixed on their affairs, and these people were corrupt. They, therefore, sought to justify themselves, because Jesus, with his simplicity, but with his strength in God, made trouble for them.

“And, step by step, they ended up convincing themselves that they had to kill Jesus,” because they “resisted the salvation of the love of the Lord.

“They rejected the Lord’s love; and this rejection put them on a path that was not the dialectic of freedom offered by the Lord, but that of the logic of necessity, where there is no room for the Lord. In the dialectic of freedom, there is the good Lord who loves us, who loves us very much! But in the logic of necessity, there is no place for God: [only thoughts of] this must be done; this must be done. This must! …They have become behavioral: men of good manners but bad habits. Jesus calls them ‘whitewashed tombs.’ This is the pain of the Lord, the pain of God, the lamentation of God.”

Pope Francis then invited the legislators to consider Lord’s invitation given to them, the invitation to the dialectic of freedom, where there is love.

“On this path of Lent, it will do us well to think about this invitation from the Lord to love … and to ask ourselves, all of us … am I on this path? Do I risk justifying myself and take another path?”

“We pray,” he concluded, “that the Lord gives us the grace to always go down the path of salvation, to open ourselves to the salvation that only comes from God, through faith — not from what was proposed by these ‘doctors of duty,’ who had lost the faith and who led the people with this pastoral theology of duty.

“We ask this grace: Give me, O Lord, the grace to be open to your salvation. Lent is for this. God loves us all: He loves us all! Make the effort to be open. This is all he asks of us: ‘Open the door. The rest, I will do.’ Let us allow him to come into us, to embrace us and give us salvation.”