This is a rhetorical question that James uses to scold his audience. It can be translated as a statement: "No one knows what will happen tomorrow." (See: [[rc://en/ta/man/translate/figs-rquestion]])
This is a rhetorical question that James uses to teach his audience about physical life. It can be translated as a statement and as a new sentence: "Think about your physical lives."
## For you are like a mist that appears for a little while and then vanishes. ##
This is a simile that compares how quickly physical lives are quickly end to a mist that appears then quickly goes away. This could be translated as "You live for only a short amount of time, and you do not know when you will die." (See: [[rc://en/ta/man/translate/figs-simile]])