2. The body is not rotting
Many saints after death, their bodies not only did not decay, but also gave off a very sweet, planty scent, and this was said to be a sign of holiness. For example, Saint Bernadette Soubirous, who died between 1879 and 1909, a bishop exhumed her body, and discovered that the saint's body had not rotted at all. Currently, Saint Bernadette Soubirous is on display at St. Bernadette in France.
Or the body of Saint Giovanni da Triora is placed under the altar of Heaven of the church of Saint Mary in Rome. For many years, the body showed no signs of decomposition, making many people find it hard to believe.
The Catholic Church believes that the reason saints' bodies do not decompose after their death is because God gave them a miracle. This answer is not accepted by the scientific community. Therefore, experts continue research projects to find the answer soon.