If everyone who is saved goes to heaven, who will be on Earth for Satan to deceive when he is let loose again in Rev 20:7?
Going to heaven is a matter of timing. People do not go directly to heaven when they are saved. Otherwise, when someone is baptized into Christ, they would disappear! Saved people go to heaven after they die. There will be plenty of people alive on Earth, saved and unsaved, when Satan is let out of prison at the end of the thousand years.