But before I get into that I want to make something clear about God's hiddenness- it can seem very subjective. I firmly believe that those who are truly looking for God will find evidence for Him everywhere- He is not hidden to those who are looking. These people are those who desire to work against their sin nature, to become more like God.
On the other hand, those who are not looking for God with the true intent to follow Him do not find Him. Some even say that they see NO evidence for God whatsoever- regardless of the evidence provided by apologists, scientists, and philosophers. A believer and an unbeliever can look at the same thing; one will see it as evidence for God, while the other does not (I discuss this more in my post Evidence For vs. Proof Of).
But I just have to wonder if God has a purpose for being hidden from those who will never come to Him- those who hear the gospel message, know the story of Jesus Christ's sacrifice, yet still choose to reject God.
We've spent several weeks already going over what man's problem is (sin). Christianity teaches that God works out all things for the good of those who love Him (Romans 8:28), that God has a purpose for everything He does or allows to happen.
When I see the actions on the news (murders, rapes, scandals, wars, torture, etc.) committed by those who do not believe that a God exists, who does have a purpose for allowing such things to happen, I wonder if their future possible understanding and belief that a Being does have a purpose for what is allowed might be taken as license to do much more evil than what they currently do.
However, I do not think that I have to relegate this to my imagination. All I need to do is refer to the history of violence committed by individuals or groups who claimed affiliation with God. I can also look at the daily news and see terrorist attacks done in the name of God. Finally, I can look to the Apostle Paul. He spoke against this exact thing: "...Shall we go on sinning so that grace may increase? By no means!..." (Romans 6:1-2) Not only do we see that this is a real and active implication of God's visibility, but God is also aware of it.
Most of us would agree that there is enough religious violence as it is. It surely seems that God agrees and has taken steps to prevent more without violating man's free will to choose their own behavior. It could very well be that God purposely remains hidden to those bent on doing evil to prevent them from justifying more than what they already do. Logically if someone, who has chosen to exhibit an evil behavior, believes that their behavior will always lead to something good or further that it will lead to the final overcoming of evil, they could justify constantly doing that evil "because God allows it and will always have a good purpose for it". However, if God remains hidden from these people, they do not have any way to make such a rationalization- thus some restraint will take place.
God knows the heart of every human being. He knows if the true desire of individuals' hearts is to seek their Creator and Savior until death. He also knows if the true desire of their heart is to remain morally independent until death. God's decision to remain hidden to the second group may very well be an act of mercy towards those who come in contact with such a person (saved or not).
Not only is the hiddenness of God not inconsistent with God's character, it is practically demanded if God is loving and allows humans to freely choose their behavior and posture towards their Creator- making them fully responsible for the consequences of their decisions. The hiddenness of God is consistent with his love, mercy, and justice.