In the nave of Cologne Cathedral on Friday, an abundance of color shone through the stained glass windows, bathing the 1,400-strong congregation in a warm glow.

"The memorial service should give comfort," Cologne's Cardinal Rainer Woelki told the congregation at the ecumenical ceremony, which included more than 500 relatives of the crash victims.

Outside the cathedral, hundreds more citizens, tourists and passersby stood in silence to remember those lost on March 24.

As the sun reached its peak at midday, wreaths laid out in front of the huge 'Dom' by Lufthansa, the state of North Rhine-Westphalia and the German pilots' union Cockpit were cast into darkness by the cathedral's looming shadow as the city seemed to pause to reflect during the two-hour service.

'No one is to blame'

Placing a white rose beside floral tributes was Fatima Uesugi. The 68-year-old had traveled from Morocco to Cologne to be at Friday's ceremony. She had lost a family friend in the crash.

"I'm here to represent my son," she explained. "He married into the family who lost a relative. They have suffered much loss," Fatima said.

A mother of a pilot herself, Fatima said, "Pilots should be given more time off."

"No one can be specifically blamed. But this is a stressful job. Pilots are often placed under too much pressure," she added.

Mourners, citizens and tourists united

Among the crowds watching the ceremony on Friday were several tourists, many of whom had arrived through the city's bustling central station, which, behind the glass doors separating commuters from the peace on Cathedral Square, continued in its hectic daily routine.

But on numerous occasions, I was asked what was happening by someone struggling to make their way to the train station under the weight of their luggage, only to see them return moments later to lay a flower at the front of the crowd before continuing on their journey.

Others stayed for the duration of the service, settling down among their suitcases to pay their respects.

They included 18-year-old Carina Rodrigues and 19-year-old Vaness Degani, who were on holiday from Switzerland.

They were flying home later on Friday and felt particularly moved by the crash because of the 16 high school students on board flight 4U 9525, who were returning from a school exchange near Barcelona.

"It's so sad. Imagine that," Carina said. "I'm flying home today and my mother is waiting to pick me up. Then the plane suddenly crashes and we never see each other again."

"It certainly makes the tragedy feel closer to home," added Vaness.

'Who are we to judge?'

Back inside the cathedral, 150 candles flickered on the altar in front of Cardinal Woelki and the leader of the Protestant Church of Westphalia, Annette Kurschus. Each light represented a life lost in the Germanwings crash. The presence of a candle for co-pilot Andreas Lubitz had been widely debated prior to the service.

Investigators believe Lubitz locked the pilot out of the cockpit before deliberately setting the plane into a rapid descent over the French Alps that ended in its destruction. It has since emerged that he had a history of depression and had a doctors' sick note, meaning that he should not have been flying on the day of the crash.

Outside, on the doorstep to Cologne Cathedral, mourners were full of empathy for Lubitz' family, who had chosen to not attend the ceremony.

"Who are we to judge?" asked a 28-year-old Canadian, who requested to be named as Keith. "Obviously there was something going on with him for him to do that," he added. "There are clearly lessons to be learnt in companies about addressing mental illness."

During the remembrance service, German President Joachim Gauck also asked the congregation to remember the co-pilot's family.

"On March 24 his relatives lost someone whom they loved and who leaves behind a hole in their lives - in a way that they find just as difficult to make sense of as all the other bereaved."

'Love is stronger than death'

In their hour of mourning and need, many of those grieving on Friday were still looking for answers to help lessen their shock and feelings of loss.

"I have no theoretical response to the terrible misfortune," Cardinal Woelki said. "But I can point to the answer which I believe in," he added, comparing the pain felt by relatives to that which Christians believe was suffered by Jesus on the cross.

"You are not alone in these hours of loneliness," he told grieving family members, encouraging them to take comfort in the crowds of people with them at the service. "Love is stronger than death."

A sister of one of the victims, named only as Sarah, reiterated the cardinal's words.

"Let love be stronger than the desperation in the midst of sorrow," the young woman said.

People can be angels

Each of the 1,400 mourners left Cologne Cathedral on Friday afternoon carrying a tiny wooden angel which Cardinal Woelki hoped would "strengthen, encourage, give support."

"People can also be angels," said Jutta Unruh, an emergency pastoral carer who helped relatives to cope with their loss following the crash of flight 4U 9525.

As the bereaved stepped out into the heat of Cologne's early summer on Friday, the sun, too, had fought its way past the many spires of the cathedral's elaborate architecture, casting a new light over the many flowers, which had grown threefold during the memorial service.