Possibly why it warns not to take mark is that there might be believers coming into Christ after rapture or others are born later to non believers and choose to believe during the anti christ reign. It makes sense that even during this time there will be a chance for new believers to hear gospel.
![Lp. Сердце Вселенной #60 РОЖДЕНИЕ ЛОЛОЛОШКИ [Финал] • Майнкрафт](http://i.ytimg.com/vi/YoR0pAV9FVQ/mqdefault.jpg)
Possibly why it warns not to take mark is that there might be believers coming into Christ after rapture or others are born later to non believers and choose to believe during the anti christ reign. It makes sense that even during this time there will be a chance for new believers to hear gospel.