How we cite our quotes: (Book.Chapter)
Quote #1
You may leave this life at any moment: have this possibility in your mind in all that you do or say or think. Now departure from the world of men is nothing to fear, if gods exist; because they would not involve you in any harm. If they do not exist, or if they have no care for humankind, then what is life to me in a world devoid of gods, or devoid of providence? (2.11.1)
You've heard this before, whether or not you've wanted to: keep your death in mind, 'cause it's gonna come sooner or later. Marcus is a huge advocate of this line of thought and sometimes pursues it to the edge of morbidity. In this case, he assures himself that no real harm can come to him from death, since it's ordained by the gods, who are completely benevolent. If they say it must be, then there's a good reason for it.
Quote #2
What is death? Someone looking at death per se, and applying the analytical power of his mind to divest death of its associated images, will conclude then that it is nothing more than a function of nature—and if anyone is frightened of a function of nature, he is a mere child. And death is not only a function of nature, but also to her benefit. (2.12)
Marcus strips death bare of its frightening imagery to conclude, as he usually does with this exercise, that it is nothing at all. Without emotions involved, he can see that death is a necessary function of nature, just like growing up or growing old. Without it, the universe can't remain healthy: it needs to get back some of those compounds so it can recycle them into new life.
Quote #3
Further, accepting all that happens and is allotted to it as coming from that other source which is its own origin: and at all times awaiting death with the glad confidence that it is nothing more than the dissolution of the elements of which every living creature is composed. (2.17.2)
Marcus again diffuses the terror of death by saying it's "just dissolution." We're merely being taken apart into our component parts, as though the gods were disassembling a gigantic Lego set and sorting the blocks by size and color in readiness for the next project. And that is essentially what Marcus is saying: we belong to the gods, right down to our elements, and we will return to that great recycling center in the sky for just treatment.