Am I certain? No. But I'm compelled enough to seek and to follow.
I'll close by sharing a post I came across on Into the Wardrobe, a site dedicated to all things C.S. Lewis. Adam, a regular poster on the discussion boards, wrote this beautiful expression of what moves him to seek God:
On defining God:
He is the one who's voice you hear in nature and history. If life is an idiotic noise, then we are pursuing nothing. If life is a tune and a lyric, then we are seeking the player, the singer.
These sounds are unaccounted for. They most certainly exist. You are not their source. Seeking their source, hypothesizing its nature and character, is decidedly different from whimsically postulating a fictional creature.
You may argue that God's definition retreats as human understanding advances, His nature and character retaining only what is left of the unexplainable. But Theism was a relatively late development in human thought. The Philosophers knew that human understanding could never gain any ground against purpose; the Fathers knew the same about love.
But our contemporaries have deftly won the war by declaring that their own tiny patch of conquered territory is the only land in Europe; they are the kings of everything that their eyes, closed tightly, survey. The unexplainable is no threat to human understanding, because by definition anything that humans cannot understand must not exist. Purpose and love are whimsies, figments.
But I hear the music. I'll seek its source. And if it's merely idiotic noise, I'd still rather dance than just sit there.