When did God choose those who get saved?
God had those who are saved in His sights before the world was ever created. This choice was made prior to creation, expressing His sovereignty in grace. Salvation comes only by God's grace, not by human merit, and believers can understand this after they are saved.
Les explains that only after a person is saved can they understand that God had them in His sights before the world was ever created (s510–s512). He sets this within the larger theme of God's sovereignty in grace: everyone was a hell-bound sinner deserving punishment, but some accepted God's pardon and are now set free (s488–s494). The reason believers escape judgment is not that they were smarter or more deserving; it is solely the grace of God (s499–s509). Les also uses an illustration from human reproduction to emphasize vast potential (s513–s524), but the core answer remains that God's choice predates creation.