Mariupol, Ukraine – Andriy Voytsekhovskyy held back tears, praying for Ukraine and singing hymns with a small, moving congregation in an underground church as fighting raged nearby.

In a quiet suburb of Mariupol in eastern Ukraine, the church is almost invisible from the street as it sits in the foundations of a building that was never completed. It’s unusual for two reasons – it’s underground and it’s evangelical in a country where most Christians are Orthodox.

On the uncertain first day of a full-scale Russian invasion, space was a heavenly gift to its faithful as troops closed in on the city from both sides.

As the children tumbled on rolling mattresses on the floor, too young to understand the magnitude of the events around them, their parents exchanged information and tried to decide whether they should stay or go.

Andriy and his wife, Viktorii Voytsekhovskyy, both 28, slept here.

Just after midday on Thursday, as Andriy strolled his Jack Russell Chelsea near their home in the east of the city – just 10 kilometers (96.2 miles) from the frontline with Russian-backed separatists – an attack de Grad crashed ahead of him into the window of a ground floor apartment plot, about 15 meters (50 ft) away.

“If I had gone out with my dog ​​a minute later, I would be exactly where the strike hit and that changed my mind. Before, we thought we were staying home, but now I feel like there is no safe space,” he said.

While the flashes of harrowing explosives throughout the night and morning were terrifying, the close call was the last straw.

The couple’s son, Leon, 4, quickly lay down on the floor when he heard the explosion from inside.

Living so close to the tense front line with Russian-backed separatists, he is used to the threat of war. The family even made war a game – the “evil king” wants them to be scared and they won’t give it to him. Yet when he comes, they still have to hide.

“We are not afraid of you, Evil King,” he shouted after the missile hit Thursday, pointing his hands skyward.

“Life is a fairy tale for him and a nightmare for us,” Andriy said.

As Mariupol residents awoke Thursday morning to the dreaded news that Russia had invaded, the air raid sirens sounded.

Many chose not to panic, and some even drove to work in crowded buses.

Yet by afternoon, emotions began to crumble as people lined up for hours to stock up on cash and gas in case the electricity or internet went out.

Residents of eastern Mariupol took refuge in an evangelical church [Emre Caylak/Al Jazeera]

Outside a central cash machine, Maryna Mastak, 42, and her husband prepared to flee the city with their children, leaving everything behind.

“Putin is killing people here,” she said.

Mariupol, which is close to territory held by Russian-backed separatists, is vulnerable to attack from three sides – including from the Sea of ​​Azov, where Moscow’s warships are hiding.

It escaped air raids and heavy shelling seen in Kyiv and Kharkiv on Thursday, but Russian and separatist troops are closing in on both sides and the fighting can be heard from downtown.

At the station, a father hugged his daughter as he put her on one of the few trains leaving Mariupol.

People were rushing with whatever they could carry, including their cats, heading into the unknown.

With fighting across the country, no one knows if the situation is better elsewhere.

“This train will go to Kiev. With a bit of luck. On the way here we saw a lot of fighting,” said a train guard Thursday afternoon, who did not want to be named.

“It’s just better to be in the capital,” said another passenger, Akin, an international ecology student from Nigeria.

Families decide to stay put or flee to another part of Ukraine [Emre Caylak/Al Jazeera]

In the church, people are praying for things to get better, saying they have faith that God is with them, even “when the ground shakes”.

A woman said she had been an atheist until now as she re-addressed her relationship with faith in the face of devastating conflict.

For Andriy and Vikorii, who married in 2015 when the conflict between Ukraine and Russian-backed separatists was at its worst, there is an added dynamic to this new war with Russia – Vikorii is from Moscow.

They met when Andriy was visiting a friend in Russia and Vikorii was working for Russia One at the time, a state-run television station known for its pro-Kremlin stance.

“I was so ignorant then. I didn’t even know where Russia is and where Ukraine is on a map,” she said, adding that she quit her job after ‘Andriy told him about what was happening in his home country.

Married couple Andriy and her husband Viktorii Voytsekhovskyy, who worked for a Russian channel before meeting [Emre Caylak/Al Jazeera]

“I feel so ashamed for what Russia has done. Now it looks like the end of a great nation – how can anyone forgive that?

The prospect of war just a few weeks ago seemed remote. But after asking whether or not Russia will invade, the questions now center on how long will the attacks last? How bad will it get? And what will be the human cost?

Meanwhile, Ukraine announced mobilization plans and banned adult men from leaving the country.

Andriy is afraid of being forced to fight.

“I don’t think I will be a great warrior – the first time in my life with a gun. We will only be cannon fodder,” he said. “I just don’t want my son to grow up without a father.”

Residents of eastern Mariupol have taken refuge in an evangelical church. Mariupol, Ukraine, February 24, 2022 [Emre Caylak/Al Jazeera]