(CNN) -- Sixteen-year-old Valery Bianco and his 13-year-old sister Marina Bianco take extra care in preparing and wrapping their shoe box gifts for "Operation Christmas Child."
They know firsthand what these gifts could mean to a child.
"I was almost 10 when I received my shoe box, and it was touching to receive a gift as an orphan, someone people don't care about," Valery says.
Those shoe boxes were the first gifts that Valery and Marina received during their life at a Russian orphanage.
When they were sent to the orphanage years earlier, they were not allowed to bring any possessions with them. Birthdays were not celebrated and there were no toys to be found on Christmas morning.
All the two siblings had was each other. At times, it was hard for them to see how the tough life at the orphanage affected each other.
"I would see him fight with other boys and I would run into my room and hope he was OK. There were so many fights," Marina said.
For Marina, the shoe box gift came when she needed it the most. She was 6 years old when it arrived. At that point, she was becoming very angry, finding herself in a lot of fights as well.
She started believing that she had nothing to fight for.
"I did not care what happened to me," Marina said. "People would want to beat up on me. I thought, well that is what life is. But when I received the shoe box, I realized that someone did care for me in the world, and I thought that I should live a good life."
Her shoe box had the simplest items: A small towel, a few toiletries, a coloring book and stickers and a small stuffed animal.
For Marina, these possessions meant she was worth something.
"I realized you can be anyone you want, that you can control your own life," Marina said.
Four years after receiving those first gifts, Valery and Marina were adopted by a family in the United States. As they were adjusting to an American life, learning English and a different culture, their new older sister came home from school one day with a shoe box present that she was wrapping for "Operation Christmas Child."
The "Operation Christmas Child" program was started in 1993 by Samaritan's Purse, a Christian international relief group. That first year, Operation Christmas Child collected 28,000 shoe box gifts. Since then, the organization has received more than 8 million shoe boxes, which have been shipped to more than 100 countries.
For this holiday season, they are accepting gifts through December 25 and have created a "Build-A-Box" online tool, where the gifts can be virtually selected and purchased. Then a Samaritan's Purse volunteer packs and wraps the shoe box gift.
"I knew how it felt to receive that box, how it changed my life. If there is a person right now, a child in trouble, thinking of running away, that box could comfort him. That is how I felt," Marina said. "I realized I could help others."
As Marina started her own shoe box to send, she included a coloring book, a toothbrush, hard candy, a ball and a puzzle.
In Russia, she loved puzzles because they would give her a focused activity during the many hours she was alone with her thoughts in the orphanage. Valery's shoe box had similar items, but he made sure his also included a toy car. It brought back memories of the one he received in his shoe box gift.
"I know they will have fun with that, I know I enjoyed it as a kid. I put my love in there and what I thought would comfort them. To let them know this is for you. You can own something now," Valery said.
One ingredient requested for every shoe box, whether built online or prepared at home, is a personalized note of encouragement for the child who will receive it. Marina's note was easy for her to write.
"I told them about myself, that I received a box, and that I hope this box touches their life. I also wrote my address and e-mail in case they ever wanted to reach me," Marina said.
When Valery thinks of a child reading his words of support, he recalls the note he received.
"I used to think about who sent my box, I wondered what they were like and what they enjoyed doing. I knew it was a good person with love in them," Valery said.
Valery and Marina were silent as they wrapped their shoe boxes and realized that they are now the people making a difference.
To find out how to participate, order materials or find shoe box drop-off locations, call 1-800-353-5949 or go online to the Samaritan's Purse Operation Christmas Child.