It is significant that, when approaching the tender topic of death, Paul and his missionary partners once again address their readers in familial language as brothers and sisters. Instead of speaking directly about the fact that some Thessalonian Christians have recently died, Paul employs the familiar euphemism of sleep to refer to death and dying. He does not want the surviving members of this faith community to be ignorant concerning those who are asleep, in other words, those who have died (NRSV).
Page 170