everyones name was written in that book. Christ paid the price of having your name written in it.
no ones name is blotted out unless they die having rejected the cross as payment for sin,
You do not pay to have your name written in the book by your lack of sin. the law condemns you. thus you can;t be good enough to pay your own debt.
This thought rightly divides with Luke 10.20 and to expand just a bit here.
Everyone's name is written in heaven both in the old and new covenant and then depending on your choice to receive Jesus or not to it is blotted out.
This is proven by Luke 10.20, the 70 that returned were not under the new covenant yet, because Jesus had not yet been been to the cross or raised from the dead and Jesus himself said their names were written in heaven.
Luke 10.20
[SUP]20 [/SUP]Nevertheless, do not rejoice in this, that the spirits are subject to you, but rejoice that your names are written in heaven.”