Paul talks about believers who have died, who are still alive, and those who will be alive when Christ returns.
This can be stated in positive form. AT: "We want you to be informed" or "We want you to know"
Here "brothers" means fellow Christians.
Here "sleep" is a euphemism for those who are dead. (See: rc://en/ta/man/translate/figs-euphemism)
"because we do not want you grieve like the rest"
"like people who do not confidence in the future promise." It can be stated clearly what those people do not have confidence. AT: "like people who do not have the confident assurance that they will rise from the dead" or "like people who do not have the certain expectation of rising from the dead"
Here "we" refers to Paul and his audience. (See: rc://en/ta/man/translate/figs-inclusive)
"rose to live again"
Here "fallen asleep" is a polite way to refer to having died. (See: rc://en/ta/man/translate/figs-euphemism)
"Word" here is a metonym for "message." AT: "by means of understanding the teachings of the Lord" (See: rc://en/ta/man/translate/figs-metonymy)
"when the Lord returns"