But boxing, Rosado said, has never been an excuse for him to miss church.
"I sparred 13 rounds last night, and then I ran three miles. So when I slept, I was gone," said Rosado, who will fight WBO titlist Peter Quillin (29-0, 21 KOs) on the undercard of Bernard Hopkins' light-heavyweight title bout at Boardwalk Hall.
"When I woke up, I was like, 'Oh, man.' I texted my coach real quick and said I wasn't going to make strength training. I had to go to church."
Listening to his mother's sermon is nothing new. Rosado said he "practically grew up in the church."
Before separating when their only son was 13, Rosado's mother and father, Encarnacion Rosado, were co-pastors at the Church of the Sanctuary at Germantown and Indiana Avenues. They ran a ministry for men with drug and alcohol problems at a time when the North Philadelphia neighborhood was becoming notorious as "The Badlands."
"We went into the community and cleaned up. We took food and clothes to the homeless," Ortiz said. "And he saw all of that."
The 27-year-old Rosado (21-6, 13 KOs) will pray on Saturday as he does before each fight. But he will not be asking for a win. That's not how God works, Rosado said.
"I just say, 'God, whatever happens is your will,' " Rosado said. "His will is better than mine. I might want my own thing, but God knows best."
When her son was a teenager, Ortiz said, there was a moment when "Gabriel was going another path." Phone calls from teachers had become the norm before Rosado dropped out of Roxborough High School.
Ortiz no longer knew what to do. She prayed for help.
Soon after, the then-18-year-old Rosado left his North Philadelphia rowhouse with a basketball and returned with a pair of boxing gloves.
He told his mother he was going to be a boxer.
"A what?" Ortiz replied.
Before Rosado was born, Ortiz said, she prayed for a son. She would make sure he became a preacher like his parents.
But this, she said, was God's answer to her prayers. The sport was a way to channel Rosado's energy and give him focus.
Rosado began working with Billy Briscoe, his current trainer, and fought just 11 amateur fights before turning professional.
The amateur scene resembled an underworld, Ortiz said. She recounted accompanying her son to a match "in a basement somewhere." The lighting was dark, the ring was shoddy, and water dripped from a ceiling pipe.
What in the world is this, she thought.
"And now," Rosado said, "We're fighting in Madison Square Garden, MGM Grand, Boardwalk Hall."
The path from murky basements to boxing glitz came at a price.
Until recently, Rosado balanced his ring career with an assortment of jobs.
He pushed carts at ShopRite and was a maintenance man at Father Judge High School. He changed trash bags at the Plymouth Meeting Mall, worked the graveyard shift at a Home Depot, and was a contractor for the water company.
"I never doubted God. I never lost my faith in God," Rosado said. "My whole thing is when things go wrong, I know it's me not doing my part."
On Sunday morning, the 50 or so congregants of Ortiz's Mascher Street church will filter in and sing with the three-piece band before she steps to the pulpit.
And if it is God's plan, they will be listening to the mother of Philadelphia's newest world champion.