What does the Bible say about the certainty of death?

The Bible clearly teaches that death is certain for all humanity. In Hebrews 9:27, it states, 'It is appointed unto men once to die, but after this the judgment.' This underscores the reality that no matter one's earthly achievements, all will ultimately encounter death. In 2 Samuel 1, David reflects on the fallen kings, Saul and Jonathan, emphasizing the transient nature of life and the inevitability of death. This serves as a reminder for believers to live with an awareness of their mortality and to consider their standing before God when that moment comes (Ecclesiastes 3:2).