Pastor Robert Jeffress has warned that America's "collapse is inevitable" and the "implosion is coming" -- unless there is a drastic spiritual revival.

During a recent interview with conservative TV and radio host Sean Hannity, Jeffress, who pastors the 12,000-plus member First Baptist Dallas and is one of President Donald Trump's closest spiritual advisers, warned that "unless there is some great spiritual revival, America's collapse is inevitable," Charisma News reports. 

He explained that nations collapse the same way buildings are demolished: explosion, delay as the weakened structure buckles, and then sudden collapse.

"Over the last 50 years, there have been three explosive decisions by the United States Supreme Court that have so weakened the spiritual and moral infrastructure of our country that our collapse is inevitable. The explosions have already happened; the implosion is coming. We're living in that period of delay," said Jeffress.

The pastor pointed two three specific rulings that have contributed to the demise of America: Engle v. Vitale, the first of a series of decisions banning religion from the public square; Roe v. Wade, which legalized abortion; and Obergefell v. Hodges, which legalized same-sex marriage.

"No nation can survive that outlaws the mention of God in the public square, celebrates the killing of its own children and destroys the most basic unit of society, the family," said Jeffress.

That's why it's important for Christians to be "salt and light" in America, he said.

"God created government for the very purpose of restraining evil. It is one of only three institutions created by God along with marriage and the church. That makes it holy," Jeffress explained. "Every time we walk into the voting booth, we are casting a vote for righteousness or a vote for unrighteousness. And when we stay at home, we are saying, 'I don't give a you-know-what about our country.'" 

"The only way to change the direction of America is by changing the hearts of Americans," Jeffress added, quoting the words of his predecessor, Dr. WA Criswell: "The nation cannot turn to God if I do not turn to God. The nation cannot repent if I do not repent. God doesn't win nations or companies or crowds or throngs; He wins souls-one by one. And the only way we can lift our nation Godward is if I am moved Godward."

In a recent blog post, Jeffress said that two signs of the End Times are spiritual deception and international conflict -- and warned that the world is seeing both of these things with increasing "intensity and frequency."

"Jesus had a lot to say about His second coming," the pastor said. "In Matthew 24, He mentioned several signs would precede His visible return to earth. As we look at these signs, we must understand that in one sense many of these things are taking place right now. Throughout history, many of these signs have taken place. But Jesus said before He comes, these things will increase in intensity and frequency."

The first sign, Jeffress said, is "spiritual deception," and while there have been "religious charlatans" in every age, the number of false teachers has increased in recent years.

"Paul wrote in 1 Timothy 4:1, 'The Spirit explicitly says that in later times some will fall away from the faith, paying attention to deceitful spirits and doctrines of demons,'" he explained. "Toward the end, we will see a rise in Satanism and the occult. And we are seeing that right now."

The second sign of the end times is international conflict, the "A Place Called Heaven" author said, citing Matthew 24:6-7: "You will be hearing of wars and rumors of wars. See that you are not frightened, for those things must take place, but that is not yet the end. For nation will rise against nation, and kingdom against kingdom."

Jeffress admitted that since the fall of mankind, the world hasn't been peaceful. But today, we are seeing "international conflict on an unprecedented scale around the world."

"Jesus said this is a sign of His soon return," the pastor said.