God is the creator, sustainer, and purpose behind all things. But, that is not tantamount with being the author of evil. That’s why Satan exists. Satan is the instrument through which necessary evil occurs in God’s universe. Think, for instance, of how God used Satan to bring calamity to Job. God allowed it and limited the extent of it. But, it was Satan who performed it.
Or, who brought about the fall in the Garden of Eden? Satan. But, was that God’s design? Yes. Christ is the “lamb slain from the foundation of the world.” (Rev. 13:8) Why have a sacrifice prepared prior to creation unless the Fall is ordained and inevitable? But, God did not sin in ordaining the lapse. He used an intermediate cause: Satan.
Everything God does is designed to bring Him the greatest glory. And that includes His control over the events of human history and celestial eternity. The responsibility for everything that occurs in God’s universe can rightly be laid at His holy feet. But, that is not the same as charging Him with evil, which no man can do.
Isa 45:5-7 — “I am the LORD, and there is no other; Besides Me there is no God. I will gird you, though you have not known Me; That men may know from the rising to the setting of the sun That there is no one besides Me. I am the LORD, and there is no other, the One forming light and creating darkness, causing well-being and creating calamity; I am the LORD who does all these.”