In the Bible, faith is not said to be needed in order to believe that God exists. Rather, faith is needed to believe that what God says is true. This is the greatest temptation to doubt: “Did God really say…?”
God speaks, and if He didn’t, we wouldn’t exist. The atheist says he doesn’t believe in God. That’s what he thinks, but what he really doesn’t believe in is that God speaks, and speaks truthfully. God’s existence goes without saying — God is the unspoken Speaker. The atheist would disagree, but that’s because the conditions of proof for God in his mind are incompatible with reality. The atheist demands that God be an objective product of speech. Whose speech? No one’s.
“The atheist says, ‘Believe me that there is no God.’… He invokes your and my belief in the power to speak the truth… Atheism is self-contradictory, because to speak means to believe in God — to say something that has validity before and after my physical existence.”
God says, “I am,” and all of humanity hears it. To make the claim that God does not exist is really not a valid claim, and anyone who makes it is really saying that he doesn’t believe God’s claim. We all have a belief in God built into us. We all have to choose to believe if God speaks truthfully or not. The atheist takes one extreme and believes that God is lying always. The Christian takes the opposite extreme and believes God never lies (although, he will struggle much with that belief). Most people live somewhere in between those extremes.