If you want to be a good person, you need to understand all the tactics of bad people and scoundrels.

If you want to avoid being trapped or deceived, you need to understand the schemes of gold diggers and cheaters so you can prevent yourself from being scammed, harmed, or deceived.
Know your enemy and know yourself; in a hundred battles, you will never be defeated.
Know those tactics, but don't use them yourself.
Firmly refuse to do evil and only use proper and legal methods.
It's best to find ways to distance yourself from those wrong people early on and avoid entanglement with them, because they will continuously set traps with no moral boundaries.
Whereas righteous and virtuous people have many scruples.