WASHINGTON – Christians across the United States are once again preparing to mark the National Day of Prayer, an annual event America has observed for 65 years.

Organizers like Dr. Tony Evans, honorary chair for the National Day of Prayer, say that with war, terrorism, economic uncertainty, and a consequential election in November, we need to pray now more than ever.

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The prominent pastor, author, and teacher warns that "our time is running out in America."

"If there was ever a day when God's people needed to grab a hold of God and invite His manifest presence back into our midst, today is that day," Evans told CBN News.

Evans says there's power when people of faith unite.

"When you have that many people at the same time coming together to call on God about the same thing, then that creates a synergy and an awesome power of presence," he explained.

The mission is to mobilize as many people as possible across the country to pray and repent – and to acknowledge America's need for spiritual, not earthly solutions.

"It's critical because we don't have solutions to the plethora of ills that our plaguing our nation on every single level," Evans said.

"And politics is not going to, by itself, bring about the changes for right that we're desperately needing in our country," he warned.

Organizers say the call to pray for the nation is open to people of all faiths.

"Anyone can participate, but we will not compromise the centrality of our message and our commitment to Jesus Christ," Evans said.

"But we do not want to tell others that they cannot participate, as long as we're not being told we cannot herald our faith forward," he added.

Even as society's norms and values shift, Evans believes the Day of Prayer can also serve as a reminder of our national and spiritual heritage.

"The history of our country has been driven by a Judeo-Christian worldview, and so that has dominated the landscape. So it's important that we recognize the lordship of Jesus Christ without apology in our emphasis on prayer," Evans said.

This year's theme is "Wake Up America," highlighting the need to return to the God of our fathers and reverence for His holy name.