The line that separates good from evil is found in the human heart, not just in diligently following religious rituals and laws, Pope Francis said.
The outside world is not what "makes us saints or not saints, rather it is the heart that expresses our intentions, our choices and the desire to do everything for God's love," he said before praying the Angelus Aug. 30 with people gathered in St. Peter's Square.
The pope reflected on the day's reading from Deuteronomy (4:1-8) in which Moses urged people to observe the Lord's commandments without adding to or subtracting anything from them and from the Gospel according to Mark (7:1-23) in which Jesus criticized hypocrites who honor God "with their lips" but not with their hearts.
"You disregard God's commandment but cling to human tradition," Jesus said, adding that it is not the outside world that defiles people, but "the things that come out from within are what defile," including evil thoughts, theft, murder, adultery, greed, envy and arrogance.
Pope Francis said, "The boundary between good and evil does not lie outside of us, but rather inside of us."
Jesus teaches that religious rituals of purifying the body and objects do nothing without the conversion and purification of the heart, the pope said.
"Without a purified heart," he said, "one can never have hands that are truly clean and lips that speak sincere words of love," mercy and forgiveness.
A heart that is hardened or closed to God leads to a "double life" and hypocrisy, he said.
Going through the motions in "the external observance of the law" is not enough to be a good Christian, he said.
"The literal observance of precepts is something sterile if the heart does not change and if it is not translated into concrete acts: opening oneself up to God and his Word in prayer; seeking justice and peace; coming to the aid of the poor and the oppressed."
Think of the scandal and harm done to the church by those who call themselves "very Catholic and go to church often, but then, in their daily life, they neglect their family, speak ill of others and so on. This is what Jesus condemns because this is a counter-witness" to Christianity, he said.
The pope asked that everyone pray to receive "a pure heart, free from every hypocrisy" so that every Christian can "live according to the spirit of the law and achieve its end, which is love."