His books have been translated into Spanish, Portuguese, Korean, German, Chinese, Turkish, Bulgarian, Croatian, Slovenian, Czech and Italian.

His father, Roland (Orlando) was a civil engineer who worked for state government and was named personnel secretary by Christian Herter, governor of Massachusetts.

Eileen, his mother, was a physical therapist who worked at Walter Reed Army Hospital with amputees injured in the Pacific Theatre of World War II.

Merullo spent time in Micronesia during a stint with the Peace Corps, worked in the former Soviet Union for the United States Information Agency and was employed as a cab driver and carpenter.

At the close of Elegy, the reader is comfortably walking alongside a man who has grown into himself, accepted and embraced his past..."[2] A Little Love Story was published in 2005.

It is a tale about a woman with cystic fibrosis that "tinkers with traditional formula, the lovers are neither innocent nor naïve, nor completely helpless in the face of their impossible barrier to produce a love story for the 21st century..." This novel "circumscribes a dramatic arc that takes in 9/11, media saturation, lecherous men in politics, ethnic family stereotypes, adult-onset dementia, and terminal illness in the relatively young.

[4] But, Golfing with God, Breakfast with Buddha and American Savior exhibited a more overtly spiritual theme – albeit humorous in tone.

I just want to go places, to see things, to observe the human predicament in different forms... Like most novelists, I have a peculiar fascination with the way people behave and the psychological roots of, or reasons for, their behavior..."[5] In the past, film options had been secured for the novels Leaving Losapas and Revere Beach Boulevard.

In a starred review, Kirkus Magazine called it "a beautifully written and compelling story about a man's search for meaning that earnestly and accessibly tackles some well-trodden but universal questions.

"[7] In a 2015 starred review of Dinner with Buddha, Kirkus Magazine said "With six unconventionally religious novels to date, this brave, meditative author has carved a unique niche in American literature.

"[8] The Delight of Being Ordinary was released in 2017 and Publishers Weekly called it “a thoughtful, compassionate, and mature work, a 'Christian- Buddhist-agnostic prayer' to the world, and readers will find a pleasant surprise in its conclusion.

Kirkus wrote "Merullo is a long-standing, practiced hand at crafting narratives that are both hugely readable and genuinely thought-provoking, and the story of the growing relationship between his stand-in and So-Called Jesus makes for deeply captivating reading.