If God didn’t exist—or if He was unconcerned about us and didn’t care what happened to us—then you’d be right: it would be left up to us to decide what was right and wrong. We’d be like those of whom the Bible speaks: “Everyone did as they saw fit” (Judges 21:25).
But God not only exists; He knows all about us, and He cares very deeply what happens to us. And He knows that if we behave in certain ways, we’ll only end up harming both ourselves and those around us. That’s why He’s told us how we ought to live—in other words, what is right and what is wrong. And these never change—because God never changes, and neither does human nature. The Bible says, “Do what is right and good in the Lord’s sight, so that it may go well with you” (Deuteronomy 6:18).
Let me give an example to illustrate this. God has told us that it’s wrong to steal. But what happens when we ignore this? You know the answer: we mistrust others, and society begins to fall apart. God’s way is always better than our ways—always.
I can’t help but wonder, however, why you want to make up your own rules about right and wrong. Is it because you want to be free to live any way you want to? Don’t be deceived; this is a dead-end road. Instead, face honestly your need for Jesus Christ, and submit your life without reserve to Him. You’ll never regret it.