What does "Reverse 21 Grams" mean?

[MasterChiefX9999]

If anyone is confused about why this game is named Reverse 21 Grams, it's because 21 grams is commonly believed to be the weight of the human soul.
Reverse 21 Grams means the denial of the human soul or the process of gaining back the human soul. When you reach the end of this game, you will understand this.

[FleX.Kinetix]

thanks. but my mandarin is kinda sucky atm