Thank you for your interest in such important article like this. Since my childhood I knew quite number of fool Christians (Psalm 14:1) who dared Jesus by converting into Islam, leaving Jesus ashamed, the only person who in His name shall the gentiles trust(Matthew 12:18-21). Does not matter if they did not know is it the right step or not? Because after their fall nothing can help the unfaithful but woe unto that man by whom Jesus is betrayed. (Luke 22:22).
About people who have not heard nor have a corrupted picture of Jesus because of the lies written in their book, I think the Good News of the Gospel of Jesus Christ have reached even the deep rain forests by now.
Read (Romans 1:18) about the wrath of God please. This verse indicates how God still angry with man as long as man is a sinner.
I have got another article for the next Sunday about (God of the old Testaments is He a mystery?); maybe it can answer some of your questions.