Though it has its roots in Christian heritage, the National Day of Prayer is meant to be an expression of American freedom of religion, where people of different religions dedicate the day to pray for our nation.

The holiday has its origins in 1775, when the leaders of our country realized the importance of seeking the Lord for wisdom when forming the new American nation and the Continental Congress made a plea to its constituents to devote a day to prayer. Celebrated on the first Thursday of May, the National Day of Prayer was signed into law as an official day of observance by Harry S. Truman in 1952.

While its origins are Christian, the National Day of Prayer is meant to be participated in by people of all religions. "The National Day of Prayer is an annual observance held on the first Thursday of May, inviting people of all faiths to pray for the nation," the National Day of Prayer Task Force (Task Force) website reads.

Although it is not a public holiday, the day of prayer is recognized annually by the President of the United States of America, with many professing Christian presidents have historically given distinctively Christian proclamations. Bill Clinton and President Barack Obama, however, have taken care to mention that the holiday encompasses all religions. "Prayer brings communities together and can be a wellspring of strength and support," said President Barack Obama in his 2013 proclamation - "Regardless of religion or creed, Americans reflect on the sacredness of life and express their sympathy for the wounded, offering comfort and holding up a light in an hour of darkness."

Because it is not a public holiday, schools and public transport will remain in operation. The day of prayer has been challenged in court by the Freedom from Religion Foundation, but the federal court dismissed their case in 2011.

The National Day of Prayer Task Force, which is privately funded and coordinates events for the holiday, celebrates the holiday "based on our understanding that this country was birthed in prayer and in reverence for the God of the Bible." The Christian organization exists to "communicate with every individual the need for personal repentance and prayer, to create appropriate materials, and to mobilize the Christian community to intercede for America's leaders and its families." Their theme for 2014 is "One Voice, United in Prayer," calling Christians to pray both individually and corporately to "place their faith in the unfailing character of their Creator, who is sovereign over all governments, authorities, and men." It was inspired by Romans 15:6: "That together you may with one voice glorify the God and Father of our Lord Jesus Christ" (English Standard Version).

Billy Graham's daughter, Annie Graham Lotz, will be the Honorary Chairman for this year's day of prayer. Following in the footsteps of her father, the Christian evangelist will pray her National Prayer to the God of the Bible. Other speakers include Dr. James Dobson and his wife, Bob McEwen, Congressmen Mike McIntyre and Robert Aderholt, Father Patrick Conroy, and more.

The Task Force expects millions of Americans to participate, whether individually or corporately. Their website encourages prayer breakfasts and rallies, and offers resources on prayer for those interested.