Imagine that the Apostle John approached you and said, “Believe in Jesus. Later I will tell you who he was and what he did.” What would be the content of your belief? Faith must be in something. A level of understanding precedes faith. Faith then opens the door for greater understanding.
A famous 20th Century theologian, Cornelius Van Til, argued the reverse. He argued that, unless God exists, no understanding can be possible to man.