“Everything that was/is/‘will be’” is the evidence of God’s intervention. There’re many definitions because the “First Cause” implies many other things, like the Past/Present/Future/End, the Existence/Reality, but also the Maximum/Perfection/Guide/Light, and at least a dozen of other things that i haven’t perceived and/or am too lazy to add to the list, negative theology is also very interesting.
Is your only argument the old one of the existence of bad things ? There’re many answers but my usual one is that a perfect world gets boring after a while, even if that’s the goal, there’s no meaningful purpose afterwards if you think about it.
Another old answer is that suffering comes from desire(, hence, i.m.h.o., i prefer to suffer than stop desiring, and can’t complain since i ‘am responsible for my own suffering’/‘can always decide not to desire’).