Matt's father is pretty much the greatest, most important dude who ever lived. He raised Matt as a single father, sacrificed everything to make sure Matt could have the best they could afford. Jack was a pro-boxer, a guy with no real education who made his money with his fists, and he wanted much more for and from his son. He was a strict father, he was a drinker, and on occasion he did hit Matt, but Matt still idolizes him to this day. He's motivated by the desire to make his father proud, and avenging his father's murder by the mob is what inspired him to create the Daredevil persona. Basically Jack was a really flawed guy, but one Matt truly loves and holds as his inspiration. Because of Jack, Matt learned to be unafraid and to never give up.