Pope Benedict XVI is making his first official visit to the Americas, with a trip to Brazil. BBC Rome correspondent David Willey is covering the visit and recording his thoughts in a daily diary.
DAY FOUR: SATURDAY 12 MAY 2007
Pope's message on drugs
Violence, pills and drugs - I change trains in Paradise.
Pope Benedict has moved on from Sao Paulo to the Catholic shrine of Aparecida some 180km (112 miles) from here for the last stage of his visit to Brazil.
I decided to remain behind in Brazil's and South America's biggest city to gauge reaction to his visit.
Catholics receive "miracle pills" at Sao Paulo's Monastery of Light
I returned to the Monastery of Light which I had visited earlier in the week and found long lines of believers queuing to receive the "miracle" pills invented 200 years ago by Brazil's newly declared saint, Brother Antonio Galvao.
Cloistered nuns are working overtime at the convent attached to the monastery dispensing tens of thousands of tiny paper pellets each bearing a printed prayer.
The pellets are widely believed to effect miracle cures for a wide variety of illnesses.
Demand for the pills has doubled since yesterday's canonisation of Brother Galvao, a church official told me.
Then I travelled on Sao Paulo's efficient and modern underground rapid transit railway to another monastery, that of Saint Benedict, built a century ago bang in the centre of the city.
It was the Pope's home during his three-day stay here.
I had to change trains at a station called Paradise.
I could not help noticing the names of some of the metro stations I passed through: Paradise, Light, Health, Peace, Freedom.
The Sao Paulo metro reflects the aspirations of the Paulistas - as the inhabitants of Sao Paulo proudly call themselves - of the 21st century.
Hundreds of couples and families with children were taking souvenir photographs of themselves under the bullet-proof steel and glass canopy constructed specially to protect the Pope.
The authorities took no chances. Benedict would have presented an easy target to a random sniper.
He appeared many times on the balcony overlooking the square in front of the monastery to bless the crowds which kept vigil ever since his arrival.
Then I suddenly remembered that today is the first anniversary of the worst outbreak of violence in Sao Paulo's modern history.
Pope Benedict visited the Farm of Hope drug treatment centre
On 12 May 2006 there were 259 co-ordinated attacks by criminal gangs in Sao Paulo against police stations, buses, and courts of justice.
Simultaneously, mutinies and revolts occurred in 20 of the city's overcrowded prisons, organised by criminals behind bars using mobile phones.
The authorities had apparently failed to monitor and control the clandestine phone calls of the city's jailed drug gang leaders.
The mayhem went on for days. The city finally counted more than 150 dead including police, criminals and innocent bystanders caught in savage crossfire.
Practically every night on local TV this week there have been reports of shootings, armed robberies, and murders. The latest death count here so far this month is 26.
The reason for the violence is the undeclared war going on in Brazil between police and the drug gangs supplying cocaine smuggled across Brazil's porous and virtually unpoliceable borders separating the state from neighbouring Colombia and Peru.
At the drug rehab centre run by Franciscan monks near Aparecida which Pope Benedict visited this morning, the pontiff warned drug traffickers they will face divine justice for the scourge of illegal narcotics across Latin America.
"God will call you to account for your deeds," he said.
The Pope celebrated an open-air Mass in Sao Paulo on Friday
Traffickers should reflect on the grave harm they are inflicting on countless young people and on adults from every level of society, Benedict said.
"Human dignity cannot be trampled upon in this way," he added.
Brazil is the world's second largest consumer of cocaine after the United States.
Drug-related violence is a huge problem, driven by the gangs that control street-corner dealing.
The gangs also control the shipment of drugs made elsewhere in South America to Europe and the United States.
In Rio de Janeiro's teeming favela slums, gangs recruit children and engage in near-daily shootouts between themselves and with police that frequently kill innocent onlookers.
But it's doubtful whether the Pope's message to traffickers will have any impact.
"What the Pope said is important for drug users, but religion doesn't matter to the dealers," Felipe Kenji, 27, under treatment at the centre since December, told reporters.
"They'll only stop selling drugs when they die."