Joel 2:30-32

I will show wonders in the heavens and on the earth, blood and fire and billows of smoke. The sun will be turned to darkness and the moon to blood before the coming of the great and dreadful day of the LORD. And everyone who calls on the name of the LORD will be saved; for on Mount Zion and in Jerusalem there will be deliverance, as the LORD has said, even among the survivors whom the LORD calls.