The Mullett family from Pisgah Forest, North Carolina has been through Hell and back, and it was only their faith in God that got them through the tough times. Now, they spend their days trying to help others overcome their struggles through spirituality.

Duane and Cindy Mullett welcomed their first son Austin back in 1993. Austin had health problems from the beginning, but he was always a fighter, undergoing his first heart transplant at the age of 8. The Mullets went on to have four daughters, Briana, Alisha, Chantara, and Kyra, but Austin remained their only son.

Sadly, Austin’s health problems did not end with the heart transplant. He was 5 when he was diagnosed with Burkitt’s Lymphoma, followed by Squamous Cell Carcinoma at age 6. Though these are both rare and aggressive forms of cancer, he was able to overcome each.

Austin was 16 when he had to have a second heart transplant, and though it went well initially, he got a severe bacterial infection that took his life.

“From the moments after [Austin’s] birth and throughout his almost seventeen years of life, we have seen how every precious day was a gift from God,” Cindy wrote on the family’s website. “Austin’s life was filled with many physical battles, but he conquered each one with an optimistic outlook and a zeal and enjoyment of life that few people ever experience.”

“Although we will always miss Austin’s lively presence in our home, we are grateful that he is eternally set free from all the physical pain,” she continued.

After Austin’s passing, his 7 year-old sister Kyra decided to honor her big brother’s memory in a very special way.

Kyra created a music video in which she sings “I Can Only Imagine“ by the Christian rock band MercyMe as a tribute to her brother. The video opens with Kyra walking through a graveyard with her dad before it cuts to Austin’s headstone.

“I can only imagine what it will be like, When I walk by your side…” she sang.

The video shows Kyra running through fields and sitting in a church. All the while, she sings about how she can “only imagine” being reunited with her brother in Heaven.

Kyra’s video has quickly gone viral, being viewed over 72,000 times.

“Excellent!!…In Christ we can be thankful in all circumstances, knowing that God is sovereign over all things,” one social media user wrote, another adding, “Love this song so much! you all did a great job on this!”

“Love your music videos,” added a third. “This one especially. We lost our newborn 4 years ago. Our daughters keep asking when we can get the DVD.”

Check out the emotional video below!