regeneration Late Latin regenerationem (nominative regeneratio) "a being born again" (etymonline.com).
Two-fold. Some of the elect men will have to die for this truth but they will be raised up first (1 Thessalonians 4:16).
the souls of them that were beheaded... The apostles that were put to death 2000 years ago.
had not worshipped the beast The Apostles didn't follow the Roman system in their lives before.
neither had received his mark The elect will not take the chip. The
image represents the image of the Roman Empire e.g. its laws, legislation, architecture, etc (1 Maccabees 8:13-16). The Roman Empire has been reincarnated today as America.