It's easy to get disheartened when things get rough. Expectations are that something, some activity will be fun. For Jacob's boyhood friend, the going got tough and he got going...home.
I wrote the chapter where he intimately leaves, abandoning Jael and Jacob from Jael's point of view. For some reason, Jael has never liked Jacob's friend. I suspect that stems from him running away when she was begging for help. That kind of first impression is hard to shake.
But to me, Jacob's friend was easy to sympathize with. Many times in my life (MANY) I have quit when things got too hard. I shouldn't have. I wish I'd been more like Jacob, growing up. You have to keep going, no matter what. If the goal matters to you, whether it's writing a novel, honing your craft or travel cross-country to return an angel back to her home, you have to keep going. You might fail, you might get defeated but don't defeat yourself by quitting.