But I tell you that anyone who is angry with a brother or sister will be subject to judgment. Again, anyone who says to a brother or sister, ‘Raca,’ is answerable to the court. And anyone who says, ‘You fool!’ will be in danger of the fire of hell.
17 You blind fools! Which is greater: the gold, or the temple that makes the gold sacred? 18 You also say, ‘If anyone swears by the altar, it means nothing; but anyone who swears by the gift on the altar is bound by that oath.’ 19 You blind men! Which is greater: the gift, or the altar that makes the gift sacred?
3 You foolish Galatians! Who has bewitched you? Before your very eyes Jesus Christ was clearly portrayed as crucified. 2 I would like to learn just one thing from you: Did you receive the Spirit by the works of the law,or by believing what you heard? 3 Are you so foolish? After beginning by means of the Spirit, are you now trying to finish by means of the flesh?
1 Corinthians 10:13
13 No temptation has overtaken you except what is common to mankind. And God is faithful; he will not let you be tempted beyond what you can bear. But when you are tempted, he will also provide a way out so that you can endure it.
Jesus says that whoever calls his sibling in Christ a fool will be liable to judgement. In addition, anyone who calls his brother a fool is in danger of hell.
So was Jesus in danger of hell? Was Paul in danger of hell? Can Christians ever call someone foolish?
The issue here isn’t one of a universal ban. It’s an issue of hypocrisy.
If Tom calls Drew a fool for stepping on his foot, but Tom does the same thing all the time to Drew, then Tom is a hypocrite.
Certain categories of people are denounced as fools in the Bible. Atheists are an example. Hypocrites are another example.
If a politician sincerely wants to reduce crime in the city, he is a fool if he reclassifies the felonies to misdemeanors in order to make the list of major felonies smaller. He is a hypocrite, because he wants to reduce crime without actually doing anything. His efforts even prevent the outcome he is seeking.
Good intentions are not enough. This politician is actually sinning if his foolishness prevents good outcomes from happening.
Aristotle classified four virtues. They are wisdom, courage, temperance and justice.
If a soldier promises to defend his squad and hold a position, he is being a coward if he runs away. His squad dies. Cowardice is a sin.
If someone sincerely wants to help the lower-income families, and he builds free housing so that no one buys from the local blue-collar construction companies which go out of business, then he is also being a fool. Foolishness is a sin.
Cowardice is the opposite of courage, and it is a sin. Foolishness is the opposite of wisdom, and it is a sin.
God understands that people are born with different amounts of intelligence. He does not expect someone to be wiser than they possibly can be. Wisdom takes effort, but God does not tempt someone beyond their ability to be wise.
However, if someone is not being as wise as he can be, he is liable to judgement and is a fool. Sinners are liable to judgement when they hurt people. Is the soldier sinning by his squad? He only wants to live. If so, then a politician who relaxes his judgement and hurts the people he wants to help is also sinning by them. Foolishness is a sin.