Should Christians call other people fools?

The Bible states that those who don’t believe that there is a God are fools (Psalm 14:1).  While the Bible states that it is foolish to believe in such a way, it also states that we should love others and show them that love (Romans 12:9-10; 13:8).  We as Christians should not stoop to the levels of the world in mocking and ridiculing those who disagree with us (Ephesians 5:3-4).  The Bible tells us not to answer a fool according to his folly, lest we be like him; meaning we should not stoop to their level and be like them (Proverbs 26:4).  However, we are to answer a fool according to his folly, lest he be wise in his own conceits; meaning we should correct them in a lovingly way that they can understand (Proverbs 26:5).  When dealing with lost people, we should hold ourselves to a higher, holier standard of conduct, no matter what is said to us.