Bivens' wife, child and mother-in-law were killed in a small Virginia town, with police arresting Bivens' brother-in-law and charging him with three counts of first-degree homicide.
Bivens, 24, shared his experience during a service at The River Church in Danville, Virginia, on Sunday. The event was streamed live on Facebook.
The right-hander's Montgomery team was in Chattanooga, Tennessee, when he was summoned home. Waiting at the airport, he turned to social media for information.
"First headline I see is two females and a small child were gone," Bivens said. "I immediately knew that was them. I found out my family was gone over a Facebook headline. I just immediately began to scream in the middle of the airport.''
Matthew Thomas Bernard, 19, of Keeling, Virginia, is accused of killing his mother, 62-year-old Joan Bernard; his sister, 25-year-old Emily Bivens; and his nephew, 14-month-old Cullen Bivens.
"I think the hardest moment for me was when I got home and I walked in my son's bedroom for the first time and realized I was never going to see him on this Earth again,'' he said. "That was the worst moment in my life. Nothing ever will come to being, to feeling the way I felt at that moment. Then again, I know I will see him again one day, and it won't be long.''
Bivens said that during his struggle to cope he was reading the Bible verse John 16:33 and it changed him.
"And when I read, 'Take heart, for I have overcome the world,' it changed, it completely flipped a switch in my heart," he said. "And from that moment on I knew that this was not going to beat me, this was not going to beat family. I was going to live in victory the rest of my life, and I was going to use this as a testimony to show what he has done for me he can also do for others.
"That moment for me was one of the biggest moments where I just knew God was with me, and the only thing I knew to do was just laugh in the enemy's face, because he thought he had won. But all he's done is awoken a sleeping giant and as long as I'm here on this earth, every day I wake up my goal is to pile-drive him right in the face every morning when I get up.''
In the months since his family was killed, Bivens has visited with his Rays teammates and pitched in Australia. He was preparing for spring training when the coronavirus pandemic struck.
Bernard is charged with first-degree murder, and a search warrant issued in September indicated that there may have been a religious motivation to his actions. A competency review and determination hearing is scheduled for next week to determine whether Bernard is able to stand trial.
Bivens has used his faith and community to try to move forward from the inconceivable.
"It's unbelievable how much I can vividly remember from the day," he said. "And it's kind of unbelievable to see how far things have come from that day also."
Information from The Associated Press was used in this report.