Here are three challenges often posed by atheists. Thanks to daylightatheism.org/2008/09/ten-questions-to-ask-your-pastor.html. These objections can quite easily be explained by those who believe in UR. I don’t believe these challenges can be answered by those with a more traditional view of christianity
Since the Bible states that God does not desire that anyone perish, but also states that the majority of humankind is going to hell, doesn’t this show that God’s plan of salvation is a failure even by his own standard? If this outcome is a success, what would count as a failure?
Why didn’t God create human beings such that they freely desire to do good, thus removing the need to create a Hell at all? (If you believe this is impossible, isn’t this the state that will exist in Heaven?)
Is it fair or rational for God to hide himself so that he can only be known by faith, then insist that every single human being find him by picking the right one out of thousands of conflicting and incompatible religions?