Revelation 13:8 says “... all who dwell on earth will worship it [the beast], everyone whose name has not been written before the foundation of the world in the book of life of the Lamb that was slain.” (ESV) He wrote your name in the book of life before the foundation of the world. It was written there when Jesus came to seek and to save. It was written before you were born.

Why was your name written in the book? Because you were chosen. Ephesians 1:4 says "...he chose us in him before the foundation of the world." God chose you to be saved before the world began.

Jesus was also chosen. He was chosen to redeem all those whose names were written in the book of life before the foundation of the world. He also was chosen before the foundation of the world. 1 Peter 1:20 says he was foreknown before the foundation of the world but was made manifest in the last times for your sake.

God didn't make it up as he went along. He had a plan all along. He had a plan before he even made the earth.