Why did God allow sin to come into the world if He didn't want it?
Here's the answer:
God gave us the freedom to choose between right and wrong.
God could have stopped sin and evil from entering the world. He could have made it so we would never sin. But He doesn’t want us to be like robots or puppets, only doing exactly what He programmed us to do. He wants people to choose to love Him and obey Him. God gave us the freedom to decide to live for Him or to live for ourselves. Adam and Eve chose to disobey Him, and that’s when sin entered the world.
Nobody is innocent or sinless except for Jesus. Since He is perfect, He was the only one who could take the punishment for our sin, which He did by dying on the cross. Three days later, He came back to life, showing us His great power (1 Corinthians 15:3-4). The only way to get to heaven is to turn away from our sin and trust Jesus to save us. If you have trusted Jesus, you have the hope of a wonderful future in heaven with God, where everything will again be perfect as He intended it to be from the beginning. This hope makes it easier to live with joy in your heart, even in a sin-filled world.
"The Lord is not slow to keep his promise. He is not slow in the way some people understand it. Instead, he is patient with you. He doesn’t want anyone to be destroyed. Instead, he wants all people to turn away from their sins" (2 Peter 3:90).
"When anyone lives in Christ, the new creation has come. The old is gone! The new is here!" (2 Corinthians 5:17).