Should people only be allowed to live in the country they were born in?How do you decide who to let in or not?

I think the problem with people is they really have not had a chance to live really with that slice of pie as you call it to value what they got and to work for it. So many people on this planet of ours do not go to bed thinking great I am going to the local park on what I hope is a nice saturday. No they go to bed and think "thank you Mary for bringing me to this night, protect me from what is outside" protect my family in the coming day, please Mary let me get enough money to fed my baby for tommorow."