How we cite our quotes: (Book.Chapter.Paragraph)
Quote #1
"The gods only go with you, Cerdic, if you put yourself in their path." (I.8.30)
Merlin mixes metaphors here. Yes, working with "the gods" means that he believes he's just going along with fate. But he also understands that there's a certain amount of free will or self-determination in this bargain. Merlin has to seek power on his own in order to be useful to the god in the future.
Quote #2
"So you came ashore on your own in the middle of a winter's night, and in a strange country, and the god threw you straight at my feet. You and your god between you, Myrddin, make a pretty powerful combination. I can see I have no choice." (II.5.57)
Ambrosius acknowledges that Merlin isn't just being thrown around by supernatural powers; he's also using his natural cleverness to do the work of fate. This is what makes him a truly powerful character, one that even mighty kings will listen to.
Quote #3
"A man takes power where it is offered," he said again. "You have told me you don't know what god has his hand over you; perhaps Mithras was the god in whose path you put yourself, and who brought you to me. We shall see. Meanwhile, he is still the god of armies, and we shall need his help." (II.6.23)
Ambrosius gives Merlin a soundbite to live by: take power where it is offered. That leads Merlin to some shady people and places, but it definitely gives him the chance to learn all kinds of useful things. And it's true that half of Merlin's magic comes from his knowledge and his continual seeking of knowledge. The rest, of course, comes from some unknown supernatural source.
Quote #4
I could feel my bruises and my ankle ached, but for all that there came flooding through me, like a drink of warm wine, the feeling of excitement and release that came with the power. I knew now that I had had to come this way; that this was to be another of the hours when not darkness, nor distance, nor time meant anything. (II.7.51)
Merlin insists that he and Cadal go an inconvenient way through the forest, and Merlin gets thrown from his horse as thanks for it. But he knows that it's no accident that he feels he needs to be there: he will shortly find the druids' island and witness a human sacrifice from a distance.
It tips him off to Belasius' true nature and also leads to his indoctrination into druid practices. The upshot? More power for young Merlin, and a greater chance that he'll be able to do what "the god" asks him.
Quote #5
[...] I was still possessed by the same light, excited power. There was something ahead of us, to which I was being led, I knew, as surely as the merlin had led me to the cavern at King's Fort. (II.8.3)
Merlin's just getting a sense of his powers when he follows Belasius through the woods to the druids' island. He's beginning to understand that his instincts can be trusted, because they clearly come from a higher power. There always seems to be purpose in even his riskiest adventures, though it's often hard for him to see why at first. In this case, the adventure leads to greater access to old-school power.
Quote #6
"When a man's wise and gentle and good," I added bitterly, "it seems to me that any man's, every man's hand is against him. Galapas could have been murdered by an outlaw for food, or a herdsman for shelter, or a passing soldier for a drink of water." (III.4.5)
Despite the fact that Merlin has benefited from the workings of purposeful Fate, he understands that sometimes the universe is filled with chaos. This is the case with Galapas' death. Though Merlin doesn't know who exactly did the deed, it doesn't matter. He takes the lesson: life can be fragile and random.
Quote #7
If this was so, and they had brought me here because of my reputed powers, there might be some way in which I could help Ambrosius right from the enemy's camp. Perhaps after all the god had brought me here for this, perhaps was still driving me. Put yourself in his path.[…] Well, one could only use what was to hand. (III.8.19)
Merlin's still not sure about his role with "the god" and Fate, but he's beginning to put the pieces together. His "trip" to visit Vortigern feels like a detour on his planned route, but he's also willing to believe that it's all part of some plan that he doesn't fully understand.
It turns out that the cosmic plans for this encounter were laid years ago, when the vision in the crystal cave led him to the mineshaft below the hill where Vortigern's doomed tower now stands. Cool.
Quote #8
"I've learned that the god comes when he will, and how he will, rending your flesh to get into you, and when he has done, tearing himself free as violently as he came. Afterwards—now—one feels light and hollow and like an angel flying. […] No, they can do nothing to me, Cadal." (III.11.73)
After his encounter with Vortigern, Merlin finally understands: he's a minion of "the god." Nothing can ever happen to him that isn't part of some higher plan. Merlin knows for certain that they will escape Vortigern's clutches, because Vortigern is destined for death—not them. Not a bad perk to the whole supernatural deal, we must say.
Quote #9
The voice that had said so, that said so now in the musty dark of Camlach's room, was not my own; it was the god's. One did no lie awake looking for reasons; one obeyed, and then slept. (IV.2.89)
It turns out that Merlin's really the perfect vessel of Fate: he's willing to roll with whatever "the god" throws at him. In some sense, this makes Merlin a bit spineless—he's totally okay with giving into something he doesn't fully understand. On the other hand, Merlin's embracing his "purpose," which is a heaven-sent plan for his life. Who are we to judge?
Quote #10
"And you shall live again in Britain, and forever, for we will make between us a King whose name will stand as long as the Dance stands, and who will be more than a symbol; he will be a shield and a living sword." (IV.9.82)
Merlin makes a prophecy for Ambrosius that's both creepy and cool. He tells his father that he (Ambrosius) will be the beginning of great things for Britain. However, it's also clear that Ambrosius won't live to see any of it—it's from his grave that all power will come. When he comes to, Merlin doesn't remember the deets of this vision, but he does understand that playing along with destiny means the downfall of his beloved dad.