The United States of America's government system of three branches (Legislative, Executive, and Judicial) was derived from Isaiah 33:22.
Nations are vulnerable and oblivious to their vulnerabilities! At any moment, the Lord could raise up a new nation or destroy one that currently exists.
Every unsaved person will have windows of opportunities when he becomes most receptive to the gospel of Christ. The Devil works hard to keep people in darkness and will distract them by every means necessary (i.e., the death of a loved one, a crying child, a ringing phone, busyness, etc.). The salvation of a soul involves a spiritual battle that can only be won by the Lord’s intervention. There is a window of time when the lost are most receptive to the gospel, likewise suggesting only a window of opportunity for the saved to speak for Christ. This is the very reason the apostle Paul stressed the importance of the saints of God beseeching the Lord to open to them a door of utterance (Ephesians 6:19).