How you have fallen from heaven,(Incidentally, I’m inclined to use the NASB because it seems to do a better job of preserving word order than the NIV).
O star of the morning, son of the dawn!
You have been cut down to the earth,
You who have weakened the nations!
But you said in your heart,
‘I will ascend to heaven;
I will raise my throne above the stars of God,
And I will sit on the mount of assembly
In the recesses of the north.
‘I will ascend above the heights of the clouds;
I will make myself like the Most High.’
Nevertheless you will be thrust down to Sheol,
To the recesses of the pit.
On commenting on Mormonism, the Facebook poster commented, “It is kind of a problem when the goal of your religion is the first sin of Satan.”
This reminded me of a similar passage in Romans10:6-8, which was written some 700 years later. Reading the Isaiah passage again, I think the two passages have something to say to each other (by way of complement, not rebuttal).
But the righteousness based on faith speaks as follows: “DO NOT SAY IN YOUR HEART, ‘WHO WILL ASCEND INTO HEAVEN?’ (that is, to bring Christ down), or ‘WHO WILL DESCEND INTO THE ABYSS?’ (that is, to bring Christ up from the dead).” But what does it say? “THE WORD IS NEAR YOU, IN YOUR MOUTH AND IN YOUR HEART”—that is, the word of faith which we are preaching...I think that one of the issues that Paul is tilting at is unhealthy speculation about who will go up and who will go down. Another way of putting it is that Paul is urging us to avoid complicated schemes for allotting people to heaven or hell.
An important inference from this is that the Christian life ought to be focused on the here-and-now because the Word is here and now. That doesn't mean we should lose all concern for "eternal destinies", but rather they should not be our principal occupation. If we live by faith today, then we can rest assured that God will take care of tomorrow. And that applies to the rest of the human race, too.
Paul's ellipses are even more intriguing ("…(that is, to bring Christ down)"...). My reading is that Paul says something like "don't try to bring Christ down from heaven, and don't try to raise him up from the dead". Why not? Because God has already brought Christ down from heaven and raised him up from the dead.
This is of principal relevance to Paul's Gospel of Grace, because it's not our efforts that either bring Christ down or raise him up. These are the works of God, and it is our prerogative to live in the works that God has already finished (see Ephesians 2:10).
Paul previously argues that Christians are also already buried and raised from the dead, because they are "in Christ" (Romans 6:4-9). Like the resurrection of Christ, this is not something that we achieve by “trying”, but a work of God. The Christian life does require effort; however, it’s not an effort to secure our eternal destiny, or even to bring Christ into our present circumstances, but the effort to live out the (already secured) resurrection-life in our here-and-now. In other words, it's the effort required to align what we do to the reality of the situation that we find ourselves in, by the Grace of God.
Contrast this with the warning from Isaiah. In Isaiah the "Star of the Morning" tried to raise himself to heaven, rather than live by faith in God. The consequences worked out in exactly the opposite direction to those desired.
So, Isaiah and Paul unite in urging us to put our faith in God, rather than trying to exalt ourselves to Heaven. Our prerogative is not to try to lift ourselves up, or to speculate on who will go down, but to live by faith in the circumstances that God has put us in.