God is not responsible for pain, suffering, disease and death; humans are. Every sin, no matter how big or small, contributes to death. Humanity, nature and the entire cosmos are all intricately interconnected in ways we don't fully understand. A sin is like a stone thrown in a peaceful lake, and has ripple effects across space and time. All the death, calamity, chaos and disorder we have is a result of sin. A side-effect. This is the Orthodox understanding. People blaming God for disasters and suffering is misguided. It is a misconception and misinterpretation.
God gives life. Humans spoil it. And then what does God do? He saves everyone and everything.