Sometimes it's hard for us to understand why original sin brought death, disease, and sadness into this world.
And while I'm no theologian, I'd like to suggest an explanation in layman's terms. (Because, really, that's the only way I speak!)
Please, if you read something below that sounds contrary to our faith, correct me. I'm all ears.
God gave us the gift of free will because, if He didn't, then our love for him would be forced affections and not at all meaningful.
To give us the gift of free will means to make room for the fact that we may choose to disobey. And, when humans choose to disobey God, they make choices that do not stem from Love (Who God Is) but rather stem from the very lack of it.
In the Bible, we learn that Cain murdered his brother Abel. And, unfortunately, murders continue to happen today. But if God did not permit the possibility of physical death as inflicted upon one person from another, then Cain's murderous desires could never be part of his free will to disobey God.
The senseless killings that we've endured in our human history mean that scads and scads of lives were cut short. Enormous potential to do good was taken from the face of this Earth by its very inhabitants (and that "good" could have been in the areas of medicine or philanthropy or even the simplicity of an ordinary life that touches only a few people but could bring them to happiness).
Without the beneficial effects of countless good actions, we have a world of people who are suffering. People are afflicted with diseases for which we are still searching for a cure. And those diseases plague us because even Nature itself is now in unbalance as it groans with the effects of natural sin. The delicate balance of the flora and fauna in our environment and in our bodies is off-kilter. There is a sense of un-harmony everywhere, if you look closely, because all of us are yearning for a Savior.
And while our Savior has forgiven us of our sins, calls us His children, has conquered death for us, and could end all of this suffering tomorrow, He doesn't. Rather, He continues to give us the gift of free will. He continues to gift us with the lives of new people entering the world, in the hopes of making things better. He patiently watches to see if we will bring about the peace and love He taught us that are the pillars of the Kingdom of God.
Eventually, when our individual lives are over and He calls us back to Himself, He will restore us completely to full happiness and will hopefully be telling us, "Well done, my good and faithful servant."
