They’ve faced their own mortality and they face it constantly, just as Christ did
Paul affirmed that the Lord alone is the source of immortality (1 Tim. 6:16). He is everlasting in His character and actions. For human beings, however, death is universal, inevitable, and ultimately leads to judgment (Heb. 9:27). This is all a result of our sin, and it can be countered only by the redemption through Jesus Christ (John 3:15-16). Through His resurrection, Jesus broke the power of death and showed humanity the way to immortality (2 Tim. 1:10).