One who prays with humility and awareness of his or her sin speaks to God, Pope Francis said on Wednesday, whereas one who prays with arrogance and self-righteousness is speaking to a mirror.

"It is not enough to ask ourselves how often we pray," the Pope said to the thousands of people gathered in St. Peter's Square for the weekly general audience. "We must also ask ourselves how we pray, or rather, how our heart is."

The pontiff centered his June 1 catechesis on Jesus' parable of the tax collector and the pharisee.

The problem with the pharisee – who stands in the temple and gives thanks for not being like other sinners – is that, as he prays to God, he looks at himself, Francis said.

"Instead of having the Lord before his eyes, he has a mirror," the Pope said. When he prays, the pharisee lists his good deeds, and is made happy by following "precepts."

"Yet, his attitude and words are far from the way of acting and speaking of God, who loves all men and does not despise sinners," Francis said.

Thus, this pharisee, who believes he is just, "neglects the most important commandment: the love for God and for neighbor."

Francis said we must examine our thoughts and feelings, eradicating "arrogance and hypocrisy." We cannot pray with arrogance or hypocrisy, but rather "we must pray before God as we are," he said.

The tax collector, on the other hand, is shown to be humble, asking God for mercy.

Francis invited the crowds to follow the example of the tax collector, and repeat after him three times: "Lord, be merciful to me, a sinner."

The parable, he said, teaches that being righteous or sinful has nothing to do with social status. Rather, it has to do with the way we relate to God and to our neighbors.

"The tax collector's humble gestures of penance and (these) few simple words," Francis said, demonstrate his awareness of his "miserable condition."

"His prayer is essential. He acts out of humility, secure only in being a sinner in need of mercy," and in the end, he "becomes a symbol of a true believer."

In contrast, "the pharisee is the symbol of the corrupt pretense of praying, but only succeeds in showing off in front of a mirror."

"Pride affects every good deed; it empties prayer," and keeps God and others at a distance, Francis said. Humility, on the other hand, is necessary in order to receive mercy.

God has a "weakness" for humility, the pontiff said. "Before a humble heart, God opens his heart completely."

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Later in the audience, Pope Francis remarked that Friday marks the  Solemnity of the Most Sacred Heart of Jesus, as well as the start of the June 1-3 Jubilee for priests.

He invited everyone to dedicate the month of June to praying to the Sacred Heart, and "to support the closeness and affection of your priests, so that they may always be in the image of that Heart full of merciful love."