Is it possible to be cast out of heaven, considering the devil was once an angel?

What makes you think God gives folks the reward of eternal life? Eternal life is for the righteous. The vast majority of folks including many angels will have their part in the lake of molten sulfur meaning they will be cremated at that place of cremation. Satan an the 1/3rd of the angels are cast out of heaven they are driven out they don't want to leave paradise. Furthormore they all serve God until they are cast out. My guess is the actual war in heaven began in 2011 with the UFO over the temple mount its on youtube. 2011 was a big year for Bible Prophecy, the Jewish leader former Representitive Gabriel Giffords received what seemed to be a mortal head wound but is miraculously recovering as Revelation 13 indicates, Fukushima 3/11/2011 Great Earthquake an Fire fulfilling Ezekiel 39:6 an Revelation 6th seal, 1, 2, 3rd trumpet 2nd bowl, an then Syrian civil war began that week on 3/15/2011 as Ezekiel 38 indicates it would, an since then all Gog Magog Combatants have been active in Syria(which is part of ancient northern Israel.)

So the main question here is can folks loose their salvation, an I think the answer is yes of course God isn't going to save someone if they don't want to be saved. Now what does it mean to be saved, it means folks will be resurrected to reward at the beginning of the thousand years, being resurrected at that time is a reward because the majority of incredible wicked people will be resurrected a thousand years later at judgement day. So just being spared being around such depravity is salvation. Consider 100 billion people have probable lived over the last 6 thousand years, if 10 billion are resurrected to reward well that is much less crowded an in much better company than judgement day.

As for eternal life that is a reward for the righteous.
So be righteous.

There is some indication that those righteous enough to enter the new Jerusalem an have eternal life will indeed be righteous enough to coexist with the creator for eternity. But logically folks still fall down an trip or whatever an die so unless God is going to continually resurrect folks eternity is probable just a very very long time, perhaps a million or billion years I don't know. The original language greek words are vague at best.

/r/Christianity Thread