The wages of sin is death, but the gift of God is eternal life. Paul contrasts two systems: One pays wages, the other gives gifts. Sin pays with death. God gives life. And this gift is in Christ Jesus.
You don't earn eternal life. It is a gift. And gifts are received, not worked for. The old system pays what you deserve. The new system gives what you could never earn.
Today: You live in the system of gift, not the system of wages.