Vatican City, Aug 9, 2015 / 06:27 am (CNA/EWTN News).- On Sunday Pope Francis said the “horrific” atomic bombings of Hiroshima and Nagasaki are the icon of man’s destructive misuse of scientific progress, and called for an end to all nuclear arms and weapons of mass destruction.

The “tremendous” atomic bombings of the two Japanese cities, which took place the 6 and 9 of August 1945, “still arouses horror and repulsion,” the Pope said in his Aug. 9 Sunday Angelus address.

He told pilgrims gathered in St. Peter’s Square that the event “has become the symbol of man's enormous destructive power when he makes a wrong use of scientific and technical progress.”

These bombings ought to serve as a permanent warning to humanity in order “to repudiate her forever from war and to banish nuclear arms and every weapon of mass destruction,” he said.

Francis then called for prayer and a decisive commitment to work for peace and to spread an “ethic of fraternity” in the world so as to foster a serene coexistence among peoples.

“From every land should arise one voice: no to war and violence and yes to dialogue and peace!”

Seventy years ago, the only wartime use of nuclear weapons took place in the Aug. 6 attack on Hiroshima and the Aug. 9 attack on Nagasaki by the United States.

The Hiroshima attack killed around 80,000 people instantly and may have caused about 130,000 deaths, mostly civilians. The attack on the port city of Nagasaki killed about 40,000 instantly and destroyed a third of the city, the BBC reports.

The attacks took a heavy toll on all of Japan’s population. Many Americans credit the atomic strikes with ending the Second World War that began for the United States with Japan’s 1941 attack on Pearl Harbor, however this interpretation is something many others have said Americans should question.

Pope Francis has spoken against nuclear weapons before, including during a Dec. 7, 2014, message to an international gathering on the weapons.

“Nuclear deterrence and the threat of mutually assured destruction cannot be the basis for an ethics of fraternity and peaceful coexistence among peoples and states,” he said.

“A global ethic is needed if we are to reduce the nuclear threat and work toward nuclear disarmament,” the Pope explained, adding that the many victims of nuclear arms are a warning “not to commit the same irreparable mistakes which have devastated populations and creation.”

In his Angelus address Francis also offered his thoughts and prayers to the people of El Salvador, where he “follows with concern” the news of increasing hardships due to famine, the economic crisis, acute social conflicts and growing violence.

“I encourage the dear Salvadorian people to persevere united in hope, and I urge all to pray so that in the land of Blessed Oscar Romero, justice and peace will flourish again,” he said.

Archbishop Romero was killed due to hatred of the faith March 24, 1980, in the midst of the birth of a civil war between leftist guerrillas and the dictatorial government of the right. At the beginning of this year Pope Francis approved of his martyrdom and he was beatified May 23, 2015.

Violence in El Salvador skyrocketed after a treaty between local gangs and the government collapsed early last year.

According to the Associated Press, a recent spike in murders – with a reported 600 in May alone – is due to the fact that gangs are seeking to pressure the government into negotiating a new treaty, much like a previous one which resulted in a significant drop in homicides. However, the government has frequently repeated that it will not negotiate with criminals.

In his reflections on the day’s Gospel reading from John, Pope Francis focused on Jesus’ declaration that he is the true bread come down from heaven, and that “No one can come to me unless the Father who sent me draw him…He who believes in me has eternal life.”

Jesus’ words, he said, introduce a relationship into the dynamic of faith, which is the relationship between the human person and the person of Jesus. Both the Father and the Holy Spirit naturally play a decisive role in this relationship, he noted.

Pope Francis said that “it’s not enough to encounter Jesus to believe in him, it's not enough to read the Bible, it's not enough either to witness a miracle,” even though all of these things are good.

What’s needed, he said, is an open heart, because there are many who have come into close contact with Jesus, but have still not believed and have even despised and condemned him.

“Why? Because their hearts were closed, (and) when the heart is closed faith can't enter,” he said, explaining that faith is a gift from God.

“Faith…blooms when we allow ourselves to be drawn from the Father to Jesus, and we go to him with an open mind, without prejudice; so we recognize in his face the face of God and in his words the Word of God, because the Holy Spirit allows us to enter into the relationship of life and love there is between Jesus and the Father,” he said.

Pope Francis concluded his address by turning to the example of Mary, who is the first one to both believe in Jesus and welcome his flesh. He prayed that all would learn from her how to receive the gift of faith before leading those present in the traditional Angelus prayer.