1. We can’t count on miracles. So if somebody claims that by following certain religious tenets then we can end corruption, that guys just need to show us more evidence just like everyone else. We also can’t count on God doing things God don’t usually do, namely interfering in normal natural order of universe as predicted very accurately by science. That’s assuming God exist in the first place of course.
2. We can’t count on unselfish heroism. First most humans are selfish. Second, those who aren’t selfish sacrifice himself for the sake of others. Those people lessen intensives for all others to play fair.
3. We can’t count on government. Corruption is a lost for the people but is profitable for government official.