Can anyone answer my question?

If Jesus provides for us the gift of eternal life and has made provision for salvation, why is it necessary for people to still die? Why can't he just give believers eternal life immediately? why must believers face the first death?

"For the wages of sin is death, but the gift of God is eternal life through Jesus Christ our Lord." So if Jesus has paid the price, why do people have to still face death? (the first death)