Is that true? We see considerable good done by those who believe in God both as individuals and collectively as churches and denominations. For example when a disaster occurs, we see churches responding.
We also see much evil and this is associated with people who have no belief in God. Shouldn't we expect that?
Why would an omnipotent God tolerate original sin for a second.
You may be confused here. Original sin refers to the effects of Adam's sin and not to Adam's sin. You seem to be asking why God even allowed Adam to sin in the first place. Are you?
All we know is that God is carrying out His plan and His plan included Adam's sin.
God as a hypothesis is a totally failed hypothesis. Especially when the theists try to drag morality into the argument.
God supposedly is morally perfect and has free will. God then, of his own free will, never does anything morally evil. God has a good nature. Why then does not this God give all mankind a god-like good nature and a god-like free will? Romans 11, why did the Jews not believe Jesus was the messiah, the son of God. Paul tells us that God hardened their hearts to not believe. So God does not value free will. So why not just harden the hearts of all men to believe? This all makes no sense, doesn't it? Islam is even worse. "Allah leads who he will, and leads astray who he will".
This simply does not work, does it? These sort of things are usually called The Problem Of Evil, but I am going to start calling this
The ProblTheem Of The Moral Failure of a Perfectly Good God. This to sharpen the focus on why God is a failed concept, a failed hypothesis that cannot be saved.
Whether it works or not depends on God's plan. When God created the world, He had decreed all that would happen from day one until the end. Now, all is playing out exactly as God has decreed - all according to plan.
Your objection seems to be that you don't know why God is doing it this way and not some other way - and perhaps it is that you think you know better.