repentance is asking for forgiveness, but it goes beyond that. At least according to my pastor and others of my faith. Because you don't just say, "I'm sorry, forgive me". If you are repentant you say, "I'm sorry, please forgive me, and I want to to what I can to make things right with you."
In some cases, there is only so much you can do. For example if someone commits murder, they cannot bring the person back to life. But they can write a letter of apology to the family, they can speak to others about their mistake (for example if they killed someone while in a gang, they can talk to teens about not joining the gang lifestyle--if they killed someone for drug money, they can go talk to other addicts,) etc.
In most of our cases, it means that the person who left has to own their own stuff (not that we were perfect!). It means they also must admit to the need to do work. They must desire to do work. Not just show up and try to pick up where they left off...
