Here the word "they" refers to the brothers and the woman from the example.
# rise
Waking and getting up from sleep is a metaphor for becoming alive after having been dead. (See: [[rc://en/ta/man/translate/figs-metaphor]])
# from the dead
From among all those who have died. This expression describes all dead people together in the underworld. To rise from among them speaks of becoming alive again.
# they neither marry nor are given in marriage
"they do not marry, and they are not given in marriage"