The question we received was: Why did God create a world He knew would turn against Him? Let's begin by noting that God did not create a world that turned against Him. It was the man and woman God created who disobeyed Him and changed everything. With that understanding the real question becomes: Why did God create man, knowing that man would sin? There's a good answer to this question, but first let's remember why God created the earth and everything in it.
"Thou hast created all things, and for thy pleasure they are and were created" (Revelation 4:11).
God could have created a perfect earth with a beautiful garden, living creatures, but no man. That certainly would have magnified His creative nature throughout the universe and brought glory to His name and pleased Him. However, the Bible tells us that God had a very specific purpose in creating man.
"And God said, 'Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.' So God created man in his own image, in the image of God created he him; male and female created he them. And God blessed them, and God said unto them, 'Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth'" (Genesis 1:26-28).
God created man in His image to be His steward on the earth with dominion over all living creatures. This would glorify the name of the Lord and reflect His image.
"Even every one that is called by my name: for I have created him for my glory, I have formed him; yea, I have made him" (Isaiah 43:7).
The Purpose of Man
Man was created for God's pleasure and for His glory. That was true for Adam and Eve, and is true for all mankind throughout the centuries. Our purpose in life is to please God by living in a way that honors and glorifies Him, by being His steward and His ambassador on earth and by living in right relationship with Him. Borrowing from the Westminster Shorter Catechism, "Man's chief end is to glorify God, and to enjoy him forever."