Christopher's father has modeled some positive characteristics that may have influenced Christopher.
Most importantly, the dad never quit. He never gave up on Christopher and never left him alone, like his mother did. To some extent this perseverance could be considered a fault, as in his reaction when his wife left him. The mess he gets into with Christopher (the lie) grows out of Ed's persistent hope that his wife will relent and return. He expected her to return. So in a sense, he didn't give up on her till reality forced him to.
Ed didn't ever give up on Christopher, though. He got angry, yes, but he never failed in his responsibilities to his son. Even after Christopher left for his mom's house, Ed didn't give up until he found Christopher there and the police told him to go home. Still he didn't give up. He continues to build the fractured relationship with his son as the book approaches its end.
Christopher may have inherited this trait of persistence. Once he decided to go to his mother's house, he never quit until he got there. He showed dedication, strength, and bravery in a difficult situation. Christopher's mother seems a bit more fragile, as demonstrated by her fleeing from Christopher and Ed when presented the opportunity to do so by her lover, Mr. Shears.