Excepting Educated Foreigners

If America is excepting all these educated foreigners, and some of them turn out to be terrorist.You go to a doctor and you are a person of color,does this mean that you have a guarantee that your doctor is not racist.and dont care whether you live or die? Or if the doctor is Muslim does this mean he's not a terrorist.what guarantees that he's not sovereign to his beliefs first before his ethics to practice saving our lifes?