Nothing is certain but the will of God. Human civilizations come and go, its true, but if God was willing to spare Sodom if he could only find 10 righteous people, if he was willing to spare Ninevah if only they would listen to Jonah, if he was willing to be patient with Israel even after 10 out of 12 spies had decided it couldn't be done, then it is a fool's bet to wager against the power of God to bring revival to this land as he has done before.
My sister passed away recently, and I came into some old, old books that have been passed down through our family for generations. I found one book among them describing a forebear of mine named Caleb. He was a circuit riding Metodist preacher, and his story tells of those amazing days when the power of God moved among the ungodly of his day, one small snapshot of a great national revival God was initiating, one that changed America's future for the better.
So yes, things do look grim. We are up against giants, and if we were alone, if there were no God to whom we could appeal for help, I would be inclined to agree with you.
But there is a God, and he has shown us mercy in the past, even when we had lost our way, even when we didn't deserve the help. We have always been sinners. Nothing new in that. But we have at times repented, and God has been there for us. Why? That's who he is. My dad used to say, if you want to know what someone will do, look at what they have done. That applies to God as much as anyone. He has judged the unrepentant, but he has forgiven and blessed and waited patiently for those who turn from their false gods and seek Him in spirit and in truth, with all their heart, whether as individuals or as nations.
So yes, we do have serious problems. But we should not add to our idolatries and corruptions by succumbing to the grave sin of despair. It is the antithesis of faith. This world is not our home, but while we are here, we are to "occupy till he comes." We do not stop obeying God or seeking his righteousness, just because some little tin frankenweenie is shaking his tiny little fist at us. To us, he is a giant, but to God he is a bug that can be squished in a moment, if it pleases God to do so. There is simply no reason for despair. God is still in control. Be wise. Prepare. And believe.
Who is despairing? The loss of the United States, especially when it is so corrupted and repulsive to God, is nothing to despair.
"For many, of whom I have often told you and now tell you even with tears, walk as enemies of the cross of Christ. Their end is destruction, their god is their belly, and they glory in their shame, with minds set on earthly things. But our citizenship is in heaven, and from it we await a Savior, the Lord Jesus Christ..."
I don't see any sin in refusing to put faith in a nation of belly-god worshipers and enemies of salvation.P