Over the weekend, a video surfaced showing Islamic terrorists beheading 21 Coptic Christians for no other reason than for their religious beliefs. There are anywhere from 10 million to 60 million Coptic Christians worldwide. What do Coptics believe? According to Christian apologetics site GotQuestions.org, Coptic Christianity is similar to Roman Catholicism and Eastern Orthodoxy in that it emphasizes faith-plus-works in salvation as well as liturgical ritual.