No one will ever confuse the doors of Corado Fitness in Dallas for the pearly gates. But it is a fitness heaven, thanks to a man they call “El Diablo,” the devil.

"Absolutely," one gym member said. "He is El Diablo."

"He knows how to kick our butts a certain way," another added.

"He is relentless," another gym member said.

Part of the reason 35-year-old Joel Corado is so tough on his clients is because he knows what's possible when you let nothing stand in your way.

Born in Guatemala, Joel moved to the United States 14 years ago in search of a better opportunity. At the time, he had no idea what that was.

So, to get by, he worked in construction and then in housekeeping.

Eventually, he taught himself English, and after six years in America, he finally found his purpose.

Since opening his gym last year, Joel has welcomed more than 70 clients.

And he said each one means the world.

"All the people here, they have become my family," Joel said.

Everyone shared that same sentiment.

"Much more like family," one gym member said.

“It's a part of my life now," another said.

"These people are my brothers and sisters," gym member Juanita Cano said.

Cano has a neurological disorder that causes immense pain. Joel not only tailored her workouts, he even joined her on trips to the doctor.

“So he could talk to my physical therapist and figure out what can I do to help,” Cano said. “I don't know where I'd be if Joel hadn't come into my life."

Turns out, the man they call "El Diablo" is really an angel. And yet, Joel said he's the one who's truly blessed.

"I feel like I'm living my dream,” he said. “This is definitely my dream come true."