Being good, by Christian theological standards, can be defined in its simplest form as being godly. Goodness is synonymous with God. The way that the Bible defines the concept of goodness is fundamentally different from how goodness is defined by Kantian/virtue ethics (which is the system of ethics that is taught to the population nowadays).
The more good you are, the better connected you are to God. Yes, God has committed atrocities; this doesn't matter. God is still perfectly good. Since God has absolute power and constructed the very mechanisms of existence, it is the center and source of its own reality; therefore, it can't possibly be anything other than perfectly good.
God intentionally causes suffering and brings disasters. There are those who God knowingly allows to suffer for their entire lives, even if they have done no wrong. Some Bible verses:
Isaiah 45:7 - I form the light and create darkness, I bring prosperity and create disaster; I, the LORD, do all these things.
Amos 3:6 - If a ram's horn sounds in a city, do the people not tremble? If calamity comes to a city, has not the LORD caused it?
Lamentations 3:38 - Do not both adversity and good come from the mouth of the Most High?
Deuteronomy 32:39 - See now that I am He; there is no God besides Me. I bring death and I give life; I wound and I heal, and there is no one who can deliver from My hand.
Job 2:10 - "You speak as a foolish woman speaks," he told her. "Should we accept from God only good and not adversity?" In all this, Job did not sin in what he said.
The true point of contention lies in whether the believer wishes to bite the bullet and accept that condoning genocides, mass rapes, child sex, slavery and more is actually perfectly acceptable in divine contexts. If you refuse to accept this, you'd be a sinner for going against the word of God.
Therefore, all of those populations that were targets of genocide, all those men and women that were raped, the babies born with terminal illnesses or into abusive families, the virtuous people who suffer from depression and suicidality-- they all deserve it even though they weren't guilty, as it was, after all, divine intent. There are no mistakes with God. Through all of this, God remains the ultimate good. That is why nobody should be allowed to kill themselves even if they have every reason to do so.
There's no contradiction in this moral system, and it is perfectly coherent within its own framework. God is evil by contemporary standards, there's no doubt about it, but what do you value more? The scriptural definition of evil or the cultural, anthropological definition?
