Every writer knows that if there is no suspense there is no story. Readers want to feel something is at risk for the characters they are getting to know. When an outcome starts feeling predictable it's a killer. If a story does not end in a satisfying manner (whether the protaganist dies or not), it may well end the relationship between the reader and that author.
Is it the same when it comes to the story God is writing and in which each of us plays a part? I believe it is important to consider this because the answer we give determines the way we live. Living with certainty does not mean that I know every detail of the plot line of my life or history. It does mean that I am confident the story will end well. Certainty does not mean that I know exactly the best thing to do at every moment. It does mean that I am confident that my choices matter.
God is not just the writer of this story -- he is intimately involved, even to the point of experiencing our human weakness and dying. God is great, but more importantly to my getting engaged in the story, God is good. God has also shown us how to join in: "do justly, love mercy, and walk humbly" (Micah 6:8).
But what about the suspense level that keeps me turning the pages (i.e. getting up in the morning with enthusiasm and hope)? If God has it all scripted and he wins in the end, what is there for me to do? I believe that while God makes the sun come up every morning, he also waits to see what I will do with the opportunity for good. Will I surrender to the plot devices that conspire to turn me into a bit player, an expendable walk-on, or a puppet? I don't believe that has to happen.
I know that God wins in the end, but will I be there? History is full of people who started out in the Way (which is narrow), the Truth (that is personal), and the Life (that can get scary), only to lay down, fall out, or wander off. You and I provide the suspense element in the Story. God takes a chance every time he lets one of us be conceived. That is also why there is applause in heaven whenever a sinner repents and a saint arrives home at the end.