Harry could not help wondering whether [Ron and Hermione] had only agreed to come on what now felt like a pointless and rambling journey because they thought he had some secret plan that they would learn in due course. Ron was making no effort tot hide his bad mood, and Harry was starting to fear that Hermione too was disappointed by his poor leadership. (15.31)
The pressure's on for Harry and, like anyone else, it makes it harder for him to make decisions. But how can he possibly direct this journey when he doesn't even know what he's supposed to be doing? Choices are hard to make when there are zero viable options. Who knew? But this is the first real test for the group's perseverance and determination, and they all suffer from the lack of direction.
The rain was pounding the tent, tears were pouring down Hermione's face, and the excitement of a few minutes before had vanished as if it had never been, a short-lived firework that had flared and died, leaving everything dark, wet, and cold. The sword of Gryffindor was hidden they knew not where, and they were three teenagers in a tent whose only achievement was not, yet, to be dead. (15.106)
This moment, right before Ron's angry departure, is the lowest point in the journey; nobody knows where they're going or how they're going to get there, and it seems like no possible resolution is in sight.
"[Dumbledore] knew what he was doing when he gave me the Deluminator, didn't he? He – well," Ron's ears turned bright red and he became engrossed in a tuft of grass at his feet, which he prodded with his toe, "he must've known I'd run out on you."
"No," Harry corrected him. "He must've always known you'd always want to come back." (20.9)
Harry gently turns around the shame that Ron feels about leaving– as Dumbledore knew, Ron's loyalty is undying, and even though he seemed to give up, he'll always want to come back to his friends.
Harry met her eyes with a mixture of defiance and shame. He remembered the words that had been engraved over the gateway to Nurmengard: FOR THE GREATER GOOD. He pushed the idea away. What choice did they have? (25.38)
Perseverance isn't always a good thing. Here, Harry struggles with his conscience, and with Hermione, over how to sneakily slip out of his agreement to give Griphook the sword of Gryffindor. He forces himself to believe it's the only option, against his gut feeling.
What if, what if, the boy knew about the others? Could he know, had he already acted, had he traced more of them? Was Dumbledore at the root of this? Dumbledore, who had always suspected him, Dumbledore, dead on his orders; Dumbledore, whose wand was his now, yet who reached out from the ignominy of death through the boy, the boy –. (27.30)
Voldemort is frustrated and confused by one of Dumbledore's most amazing qualities – his seeming determination, even from beyond the grave. The idea that his old enemy could somehow have planted the seeds of some plan in Harry frightens and angers the Dark Lord.
"We're his army," said Neville. "Dumbledore's Army. We were all in it together, we've been keeping it going while you three have been off on your own –."
"It hasn't exactly been a picnic, mate," said Ron.
"I never said it had, but I don't see why you don't trust us. Everyone in this room's been fighting and they've been driven in here because the Carrows were hunting them down. Everyone in here's proven they're loyal to Dumbledore – loyal to you." (29.34)
Faithful Neville stands up to Harry a bit here, reminding him that he's not alone – everyone in the DA has proven their mettle, and they've just been holding down the fort until Harry returned.
"Ron, we're the only ones who can end it! Please – Ron – we need the snake, we've got to kill the snake!" said Hermione.
But Harry knew how Ron felt: Pursuing another Horcrux could not bring the satisfaction of revenge; he too wanted to fight, to punish them, the people who had killed Fred, and he wanted find the other Weasleys, and above all make sure, make quite sure that Ginny was not – but he could not permit that idea to form in his mind – .
"We will fight!" Hermione said. "We'll have to, to reach the snake! But let's not lose sight now of what we're supposed to be d-doing! We're the only ones who can end it!" (32.14-16)
Again, in a time of desperation, Hermione's the only one who keeps the group on track – despite all of their grief over Fred, she reminds her friends that they must keep going, and that the end is finally in sight – if they can only get there!
Voldemort had raised his wand. His head was still tilted to one side, like a curious child, wondering what would happen if he proceeded. Harry looked back into the red eyes, and wanted it to happen now, quickly, while he could still stand, before he lost control, before he betrayed fear –.
He saw the mouth move and a flash of green light, and everything was gone. (34.90-91)
Harry's perseverance is tested here for a moment as he awaits death – it's all he can do to maintain his dignity and hold his ground. However, as we know he will, Harry manages to stay calm in the face of his impending death.
"Do not pity the dead, Harry. Pity the living, and, above all, those who live without love. By returning, you may ensure that fewer souls are maimed, fewer families are torn apart. If that seems to you a worthy goal, then we say good-bye for the present."
Harry nodded and sighed. Leaving this place would not be nearly as hard as walking into the forest had been, but it was warm and light and peaceful here, and he knew that he was heading back to pain and fear of more loss. (35.94-95)
Yet again, Harry chooses to plow ahead and do the right thing – but it's hard. He's been walking down a long, dark road in this novel, and when he thought he got to the end of it, it still wasn't actually the end… but he'll keep walking, anyway.