Many people who work against the goodness of God do so because they think that if they were doing something wrong and/or if God really existed, they would be punished on the spot. Since they are not punished (and indeed many seem to live normal or even wealthy lives) they assume that God is not watching, does not exist, or they weren't sinning. This is stupid beyond belief. If you actually read the Bible (or the Qur'an) you'd know that generations of evil dictators, greedy plutocrats and sinners lived full lives on earth and their judgment comes when they die and are cast into hell. There is nowhere in the Bible or Qur'an that promises instant judgment. In fact, much of those holy books are dedicated to warning that people live one (that is 1) life and that they will be judged when they die, with hell as a real potential outcome. Jesus warned that the road to hell is very wide. So it is a total modern hedonistic fiction that if God existed and were really angry that he would smite (punish) at the time of sin. Any idiot who can read history can see that the world is not set up that way. Even Cain, who killed his brother, was protected by God from punishment by humans and allowed to live out his life.
This is because God desires that even the most wicked should some day repent and be saved. If God had to punish in earthly time on the spot each wicked deed there would be no humans on earth, only innocent animals. In the Bible you will read that several times God ponders if that would not have been the best thing to do, to leave the earth only for the animals.
However, God does intervene and punish some evil people on the spot. That is what the Bible calls "the hardening of the heart." This means that God decides to not give further chances to repent to the person. So they might fall ill and perish sooner than people expect, for example. God does not send the illness but he allows it to happen because he has turned his back on that person. So an aircraft failure or bad judgment, for example, might be fatal where it is possible that if the person had lived a good life that mistake could have been caught before it's fatal outcome... and of course you can forget miraculous healings in those cases too. God has a bias toward saving, and through the guardian angels and the Holy Spirit he is constantly pressuring people to be good and to be charitable toward each other. It's like a gentle and clean breeze that blows all the time, but most people don't notice it. The planet would be unlivable by humans without it, so you'd know if it were gone, as life would be unbearable. But most people do not notice it. When a person crosses the line with God, God is liable to harden his heart toward that person, which is to basically stop the breeze that could lead to the person repenting. That's because the person is doing so much damage that it catches up with them (like a drunk driver) or because God has come to believe the person will not repent, or will only do so on deathbed after damaging many innocent souls through their actions.
So do understand that this is why God does not "smite" on the spot, but that he does and will intervene through what the Bible explains in several places (including the words of Jesus) "the hardening of the heart."