In this blog, we constantly emphasize the fact that we are finite. We are limited in our knowledge of both material and spiritual matters, in our ability to know good and evil, in our capacity to know what is true.
I wish God had constructed our existence differently. I wish he had given us indisputable proof that he exists, that the Bible is his word to us, and that Jesus rose from the dead. But he did not and we must deal with that fact.
While our knowledge of what is true is so limited, we still must make decisions in life. Poincaré describes our predicament so eloquently:
We are ignorant, and yet we must act. For action, we have not time to devote ourselves to an inquiry sufficient to dispel our ignorance. Besides, such an inquiry would demand an infinite time. We must therefore decide without knowing; we are obliged to do so, hit or miss, and we must follow rules without believing them. What I know is not that such and such a thing is true, but that the best course for me is to act as if it were true. 
Even our entertainment expresses the idea that we must act without knowing. The movie Second Hand Lions has a scene in which Hub gives a speech about what every boy needs to know about being a man. Hub tells Walter:
Sometimes the things that may or may not be true are the things that a man needs to believe in the most—that people are basically good; that honor, courage, and virtue mean everything; that power and money. . .mean nothing. . .that good always triumphs over evil. . .that true love never dies. It does not matter if they are true or not. . .a man should believe in those things because those are the things worth believing in. 
So how do we decide what to believe; how do we decide how to live our lives?
 Henri Poincaré, The Foundations of Science (Lancaster, PA: The Science Press, 1946) p. 158.
 Tim McCanlies, Director. Secondhand Lions. With Michael Caine, Robert Duval, and Haley Joel Osment. New Line Cinema, 2003.