The Stories That Tugged at Our Heartstrings in 2015

Our faith in humanity has been restored.

— -- Though tragedy has struck so many corners of the world this year, there were also several heartwarming stories that restored our faith in humanity.

Here's a look back at the stories that tugged on our heartstrings in 2015:

Even in overwhelming tragedy and lost, Paris resident Antoine Leiris found the courage to still love and live unafraid.

Less than three days after his wife of 12 years was killed in a of attacks in Paris on Nov. 13, Leiris posted an open letter of defiance on Facebook addressed to his wife's killers. The letter went viral.

"We are just two, my son and me, but we are stronger than all the armies in the world," he wrote. "He will eat his meals as usual, and then we are going to play as usual, and for his whole life this little boy will threaten you by being happy and free. Because no, you will not have his hatred either."

Read the full letter in English here.

Dad Refuses to Give Up Newborn Son With Down Syndrome Despite Being Threatened With Divorce

Samuel Forrest's baby, Leo, was born with Down syndrome. But immediately after seeing and holding Leo, Forrest told ABC News his heartbreak turned into joy. He said, "I looked at this guy and I said, he's beautiful -- he's perfect and I'm absolutely keeping him."

Though Forrest's wife told him that she would divorce him if he chose to keep Leo, Forrest stood by his newborn son.

"After what I've been through with Leo, I'm not going to sit back and watch babies be sent to orphanages," he said. "As a child with Down syndrome, that becomes somewhat of a label. If we can get around this label, we’ll see that they’re normal. They’re a little different from us, but they’re still normal.

Former Bengals Player Devon Still Announces His Daughter Leah Has No Signs of Cancer

In 2014, Leah Still was diagnosed with stage 4 neuroblastoma at age 4. But after nearly a year of intense treatment including chemotherapy and surgery, Leah was declared to be in remission in March just after her father Devon Still accepted the ESPYs Jimmy V Perseverance Award on her behalf.

And at the end of November, Devon Still announced on Instagram that he just got a phone call that Leah's "scans showed NED (no evidence of disease)! #LeahStrong."

175-Pound Pit Bull Shatters Misconceptions About the Breed

Though Pit Bulls are often regarded as fierce and violent, this 175-pound fella named Hulk proved this stereotype wrong earlier this year when online videos and photos of him playing and napping with his owners' three-year-old son went viral.

"My hope is that we can stop ignorance and change people's minds about Pit Bulls in a positive way with all this attention," owner Marlon Grannan told ABC News. "Because Pit Bulls are only in the media when bad things happen, this myth of them as monsters gets perpetuated, but it's not true. They might not be for everyone, but under a good leader and with proper training, they make amazing family and work or protection dogs."

Real-Life 'Notebook' Couple Dies Hand-in-Hand

California couple Floyd Hartwig and Violet Hartwig proved that the magical kind of love you see in movies does exist in true life.

After 67 years of marriage, the two died holding hands together at a hospice in February. Floyd had been keeping Violet company in the hospice, as her health deteriorated due to dementia.

Though the couple's death was sad, their children were encouraged by the lasting legacy of their love for each other.

"They weren’t fancy," one of their children, Donna Scharton, told ABC News. "They were just decent people that were always committed to each other, no matter the situation."

Florida Teacher Starts Each Day Complimenting Students One by One