Will Graham, Billy Graham’s grandson, shares an inspirational story on the power of trusting God’s Word. “On a daily basis I’m blessed with stories of the many ways God chose to use my grandfather to reach people around the world,” writes Will. “What many people may not know is it almost didn’t happen.” According to Will, everything we know of Billy Graham—the crusades, the revivals, the radio programs, the Presidential counseling sessions—all hinged on a decision made by a tree stump in 1949.
By the mid-point of the 20th century Billy Graham had already been a successful evangelist for Youth for Christ, as well as become the youngest college president in the country. Things were looking up for Graham, until his mentor, Charles (Chuck) Templeton, abandoned Christianity and challenged his faith. Chuck had also been a successful evangelist, but after studying at Princeton he came to believe the Bible is flawed. Chuck wanted to convince Billy the Bible was outdated and untrustworthy, and left him with more questions than answers.
At the time Graham was the President of Northwestern Bible College, an unaccredited institution which would require him to achieve an advanced degree if he wanted it to improve its academic reputation. This would require him taking off several years of preaching, but it would allow him to look into the veracity of the Bible.
Sometime after this conversation Graham received an invitation to preach at Forest Home, a Christian retreat center in California. While on campus he spent time reading the Bible where he kept noticing the phrase, “Thus says the Lord.” Billy had always believed God’s Word was true, but this phrase solidified it. One night while in Forest Home he walked into the woods, set his Bible on a tree stump, and cried out, “O God! There are things in this book I do not understand … I can’t answer some of the philosophical and psychological questions Chuck and others are raising …”
Graham then fell to his knees.
“Father, I am going to accept this as Thy Word—by faith! I’m going to allow faith to go beyond my intellectual questions and doubts, and I will believe this to be Your inspired Word.” 
In his autobiography, Billy Graham says as he stood up he felt the power and presence of God in a way he hadn’t in months. He was right. The next day he led 400 people to Christ. Most of us will not lead this many people to Christ in a lifetime. A few weeks later he held what became the historic Los Angeles Crusade, which lasted five weeks longer than scheduled.
Billy’s faith in the Bible compelled him to preach to as many as 215 million people over the course of his ministry. That’s a lot of people! As a standard of measure, it was the total population of the United States in 1975! Billy would lead 3.2 million of his 215 million hearers to faith in Jesus, and the number continues to grow. 
Here’s the thing. The Bible was alive and active whether Billy Graham believed it or not. It was true, whether he believed it or not. But Billy’s faith in the Bible resulted in millions of lives being changed. Millions of people will live in Heaven because of one man’s faith in the Bible on earth.
We should not underestimate the power of the Bible. Trusting it will help us see all of the rich truths it contains about our eternal home. It’s the foundation upon which our understanding of Heaven must be built.
 This story is taken from: https://billygraham.org/story/the-tree-stump-prayer-where-billy-graham-overcame-doubt/
 As recorded in Just As I Am, 1997.