Is that sometimes Ok to have doubts if God exist or not?

because if we see our world I don't see any sign of God, I mean God might create the world but I don't see God is helping the nations, like Libya that is suffering or helping other nations.. so God doesn't show himself? is he waiting for the last days to show himself? will God show himself or will be Jesus? why doesn't God act in this world right now because we need him no? I found out there are experiences with God but very personals, there are not experiences with a nation or people except believers in him because he doesn't show himself to those who disagree with him njo?