@simba722 i am not sure if you will get my point or not but we all have to die one day and after our death our deeds (good or bad) will be compared so that the one's who have more good deeds will go to the heaven while the remaining one's will be sent to hell now in order to keep a record of a person's good and bad deeds each person has a book on which angels right about their actions
the above sentence refers that no matter what we do its all being recorded in our book of life. hope you got my point:)
@simba722 Similar to @wishduo 's message-- "The book of life" is mentioned in the Bible. It is a list of names of people who are allowed into Heaven. According to the Bible, everyone's name was originally written in it. However, if someone does bad things, an angel might remove their name, meaning that person cannot go to heaven anymore.