Anyone who does not believe God has made him out to be a liar, because he has not believed the testimony God has given about his Son (1 John 5:10b).
One of the most common experiences of life is to act upon the word or testimony of another person. We will do the most amazing things in response to the simple declaration of a person we have never met before. I had the privilege of leading a group of pilgrims to the Holy Land. We were innocents abroad. Most of us had never been there before, and we did not know what we would run into. But we had been given assurance, by means of a letter from a person in New York, that someone would meet us at every place we landed and would help us to get through all the intricacies of entering a foreign land. On the strength of that letter, some twenty-five of us committed ourselves to the tender mercies of a stranger and discovered that it all proved true. The word of that letter proved true, and on the basis of it, we committed ourselves to a considerably risky venture.