At the recent houseparty ('camp' in Baptist argot) that one of my children enjoyed, I was pleased that the topic of theodicy was touched upon.
That is, how can there be evil when God is good: is he not powerful enough to overcome it, or is he not good?
Leaving aside the moral epistemological question of God not being good (then how is good defined: the 'earthworm' rule: it feels good to me?), the summary sheet used a couple of approaches, boiling down to the 'it'll be better later' view twinned with the so-called 'free will' defence.
Elements of both are true, but I think that the whole question is mis-founded. We usually allow ourselves to be trapped into using categories that come from elsewhere that de-personalise the question and envisage a philosphical god, not the real God.
In the Bible, from Genesis 2 on, its an entirely personal question; and the person in question is, of course 'God'. The personal aspect is that 'evil' or 'good' in themselves do not exist; rather, they are the result of relational congress: either the relationship is conditioned by love (of God primarily: God being love, but in all relationships), or it is not. If it is not, it is unaligned with the life of God, if it is, it is.
What we call 'evil' arises from rejection of God's fellowship (and it is not an 'absence' of something, as Augustine held, or a 'thing' as others have insisted, in idealist fashion); and has from day 6 (or soon after). The tree of the knowledge of good and evil is like a wedding ring: if you don't want to be with me, toss the ring; I'm not imposing on you; thus, if you don't want to continue in relationship with me (God), then eat of the tree: this is a free relationship of persons (but differs from the absolutist 'free will' defence in that it is not primarily about will in a universe of choice, but a decision in a known context between known people), and in that respect, of equals. 'Knowing' evil is, for Adam and Eve, participating in it; knowing it existentially. That's what they chose; they chose to participate in 'not-related-to-God, or 'evil' in rejecting God from their locus of conscious interest, and because of its creation-wide consequences there is no going back, until the new creation; and it is that which is required to undo the universal effects of the breach between creature and creator chosen not as general 'free will' but by an act of rejection of relationship.
We all suffer because we are unavoidably in a world alienated from God: we cannot escape (but through Christ). Those who question God as being the author of this state of affairs are typically those who would reject him; and so are hypocritical in their complaint.
The rest of the answer is in the Bible...the arc of salvation from fall to resurrection.