Revelations 20:11 says that at the great white throne, the dead, small and great, will stand before God...and whoever is not found written in the book of life will be cast into the lake of fire...
How does one get his name written in the book of life?
Well, you can't earn that entry...it is a gift, to be received....how? by grace (God's) through faith (yours)...
The gift of eternal life is offered to you because God is gracious and bestows His love upon all...and you may receive it, this invisible but nonetheless real gift, by "faith": the substance and the evidence of that which is hoped for that can't be seen...
If you have that "faith" which is spoken of here, you will demonstrate it by "calling upon His name"..."whosoever shall call upon the name of the Lord shall be saved" Romans 10:13