Revelation 13:8 tells us that Jesus is "the lamb slain from the foundation of the world." That's a pretty heavy statement. What it's saying is that before God created even a single molecule, Jesus Christ had already been slain for the sins of the world. In other words, the cross was not plan B. It is not as if God created a perfect world and said "this is plan A," but then Adam sinned, and God had to scramble to come up with a "plan B." God was not surprised by Adam's sin. God is not surprised by our present day suffering and pain. God is a God who "makes known the end from the beginning, from ancient times, what is still to come. He says: My purpose will stand, and I will do all that I please," (Isaiah 46:10). Creation, the fall, the cross, the resurrection and the future glory of the saints, are all part of God's plan to reveal His character and show Himself glorious. They are plan A.
God’s mission from all of eternity is to make Himself look good by reconciling unworthy people to Himself through the cross of Christ. He is the center of the story. We are just characters who are invited to participate in (and benefit from) His story. We have two options in how we react to this truth: We can question His character and complain that He created this broken world in the first place, or we can marvel at His kindness and compassion; that He would be so humble, so loving, so caring to enter into our brokenness, lay down His life for our unworthy souls, and fix this broken mess that we live in. He is glorious, and our broken world demonstrates it. It can't be any other way. This is plan A.
(Disclaimer: I am not at all removing our responsibility for our part in this broken world. Genesis 3 and Romans 8 make it very clear that our sin is the cause for the curses God placed upon this world. Sin is the cause of death, sickness, and suffering...but God sovereignly uses it in His perfect plan.)