answer:By understanding he has done the best he could for who he was/is. Aside from serious abuse, of course. Let him know you would like to ‘work’ on building a closer relationship, ask him what some things are that he would like to do with you. What commonalities do you share, the same humor, hobbies, interests? Go from there. Don’t force anything, just spend time together and let things unfold naturally, uncontrived, other than agreeing on some fun get togethers.