What does the Bible say about grieving for those who have died in Christ?

In 1 Thessalonians 4:13-14, the Apostle Paul encourages believers not to grieve as those who have no hope. The context indicates that the Thessalonian church was worried about fellow believers who had died before Christ's return. Paul reassures them that those who have fallen asleep in Christ will be raised and brought back with Jesus at His return. For Christians, death is described as 'sleep,' a comforting metaphor that signifies rest and awaiting resurrection, distinguishing the hope believers have from the despair faced by those outside of Christ.