Doubt and certainty have occupied the minds of human philosophers through the ages. In the face of the cocksure abuse of reason by the sophists, Socrates said, "When I think I know, that is when I know nothing." The rationalists situated certainty in the rational processes of the human mind. Rene Descartes began with the human mind; the reasoning self, when he said, "Cogito ergo sum." "I think, therefore I am." Descartes thought certainty resided in his ability to think; about that, at least, he thought he could be certain.  

When I was a college undergraduate my classmates and I had a variation on Descartes's maxim: "Cogito ergo sim," with which we greeted each other on Friday afternoon after an exhausting week of classes and late nights, meaning: "I think, therefore I might be." We felt there was very little of which we could be certain at that point. In our present postmodern cultural and intellectual malaise, perhaps the same motto may be applied to the spiritual and theological uncertainty that leads people into the patently self-destructive behavior characteristic of our age. They cannot know themselves, because they know not the God who created them. When they don't know God and therefore do not know themselves, they tend toward self-annihilation. Uncertainty about God leads to uncertainty about self.

Although we have no grounds for it, Christians sometimes also struggle with certainty. Sometimes Christians struggle with the certainty of salvation. I once heard an expression of doubt on the lips of a Christian who admitted that perhaps his name was written in heaven, but it wasn't written in the Bible and he was therefore uncertain about his salvation. Of course, this discounts the clear expressions of God's love and compassion for the world. When God loves the world, whom exactly does that exclude? Certainly not us! I am certainly part of the world. Paul the apostle was also certain about the sinfulness of all the people in the world. I don't know about you, but I am perfectly certain about my own sin and depravity. I have God's Word, logic, and my own experience to prove it to me. The older I become, the clearer it is to me that my depravity has been passed to me by my ancestors, and from me to my heirs. I am a son of Adam. Of this, I am certain. Yet, this certainty alone also drives me to believe all the more strongly that I am also an heir of the free gift of grace through my Lord Jesus Christ. I struggle to understand how I could be held responsible for the sin of a primeval ancestor. Yet, I am certain of this. However, it is more appropriate that someone could stand in my place and offer me the gift of life in place of my death. I should be even more certain of the power of God's grace to save me for Christ's sake. Of my sin I am absolutely sure. And then even more sure that "the free gift by the grace of that one man Jesus Christ abounded for" me (Rm 5:15), for it is the more likely.