EAST RUTHERFORD, N.J. — When Devon Kennard, a Giants linebacker, posted a message on Instagram about a book-reading contest that he was holding this summer, diverse lives became interwoven on a social media page and soon morphed into a vibrant book club.

The assigned books — “The Alchemist’’ and “To Kill A Mockingbird” — were dissected by dozens of fans and Kennard himself. One young man commented about the struggles he felt transitioning into adulthood. A college freshman wrote about being accepted as a tomboy by her male friends. And a mother learned something about her 12-year-old son, who was born deaf.

“I was like, ‘Wait a minute. You sound like a love expert,’” Brenda Gomez of New Britain, Conn., said recently of her son, Brendan, with a laugh.

For some, the opportunity to express how a novel had resonated had a surprisingly therapeutic effect. The unlikely counselor was a kinder and gentler Kennard, who revealed an introspective character online that was altogether different from the fearsome quarterback-hunter he plays on the field.