Every human heart has the capacity to do good or evil and to build or to destroy, but the strength to make the right choice comes from Christ, Pope Francis said.
"But why are we like this? Because we have this possibility for destruction, this is the problem," he said Tuesday during his homily in a morning Mass offered for the 21 Egyptian Coptic Christians who were beheaded by Islamic State militants in Libya.
At the beginning of the Mass, celebrated in the chapel of the Domus Sanctae Marthae where he lives, the pope prayed that God would welcome those murdered as martyrs since they had had their "throats slit for the sole reason of being Christians."
During the Mass, the pope also criticized weapons dealers as being merchants of death and accused countries who sell arms as allowing wars to never end.
In his homily, the pope focused on the wickedness in human hearts. In the first reading from the Book of Genesis (6:5-7:10), this wickedness led God to regret creating humanity and to bring about the great flood. Wickedness led Jesus' disciples to bicker and blame each other as seen in the story from the Gospel of Mark (8:14-21) when the disciples had forgotten to bring enough bread.
"Humanity is capable of destroying everything God made," including the original loving bonds of brotherhood, family and society because of "jealousy, envy and so much greed for power, to have more power," Pope Francis said.
While it may seem like a very negative thing to say, it is reality, he said; just pick up any newspaper of any political bent: "left wing, centrist, right wing -- whichever, and you will see that more than 90 percent of the news is about destruction."
The human heart is home to much wickedness, the pope said; the "weak" human heart "is wounded."
The pope said people desire full freedom and autonomy, with some saying, "I'm going to do what I want and if I want this, I'll do it. And if that means I want to wage war, I'll do it!"
"Then in war, in arms trafficking, 'Well we are business people' Really, in what? In death? And there are countries that sell arms to that one who's at war with this one and so they also sell [weapons] to this one so that this way the war keeps going."
Everyone has a capability to destroy because there is "this seed inside, this possibility. But we also have the Holy Sprit who saves us, you know. But we have to choose," he said, even "in the small things."
The propensity to destroy can be seen in little things, like gossip or jealousy, he said. People can even destroy their own family and their own children by "suffocating them" and not helping them grow.
But Christians have to "take seriously" Christ's message that people also are capable of doing good because the things Jesus says "aren't anything weird, this isn't a speech from a Martian."
The pope said that Blessed Mother Teresa -- "a woman of our time" -- shows how "we are capable of doing so much good."
"Continual reflection, prayer and discussion between us are needed in order to not fall into this wickedness that destroys everything."
Jesus constantly reminds people that he offers "the strength to accompany you in life's journey, not on the path of wickedness but on the path of goodness, of doing good for others, not on the path of destruction but the path of building: building up the family, a city, a culture, a nation."
The pope asked people to pray for the grace to "always choose well the path to take with his help and to not let us be fooled by the seductions that will take us the wrong way."