What would you say if you were asked, what is God? How do you imagine God to be? A physical and ancient man with a long beard sitting on the clouds or maybe a throne? Unfortunately, this is the view of far too many people. The problem is that this type of god just doesn’t stand up to any kind of rational scrutiny. Some examples should illustrate this point:
God cannot be physical since theism claims that God created all physical matter and that God is in fact spiritual, not physical. If God were himself physical, what would give him the ability to create new matter? The creator must always be greater that the creation, just like a painter is greater that his painting. God must therefore be non-physical.
God cannot be created. If you allow that God was created, this begs the question what created God’s created and so on in an infinite regression of creators and created gods. It’s totally illogical. But this unfortunately is the kind of question you hear from the likes of Richard Dawkins. As you go back in time, the chain of cause and effect has to begin somewhere. If there was no beginning, then it would be possible to arrive at today because you cannot traverse infinity. God there is said to be self-sufficient in that his existence is not dependent on anything else. God could also be called the “uncause cause” or “uncreated creator”
Rational enquiry can only tell us some very general things about the nature of God but it does not allow us to get inside his “mind”. So we can come to know about God’s inner working only through his own self-revelation to us. So for example, we could argue rationally that God is omnipotent but can we know whether God is trinitarian (Christianity) or unitarian (Judaism/Islam)? What does God expect of us if anything?
One definition of God might be “that being for which no greater can be conceived”. Since the greatest conceivable God would be unconditionally loving, it makes sense that God would reveal his nature and will to us. By not going so, we would be left in a world far more confusing that it already is. For example, imagine that God never told us about heaven and didn’t warn us about hell, it would hardly be fair to let us know these things only after died! But I would argue that God is in fact all good and has already revealed himself and his will to us in the person of Jesus Christ. Jesus told us about the existece of heaven and hell and what we need to do to attain heaven and avoid hell.