Why did God keep back just one thing from the people he made? Why would he make people in his image, then give them one prohibition? What was the purpose in that tricky Tree of the Knowledge of Good and Evil? Sinclair Ferguson addresses this in The Whole Christ.
I am giving you everything in this garden. Go and enjoy yourselves. But just before you head off, I have given you all of this because I love you. I want you to grow and develop in your understanding and in your love for me. So this is the plan:
There is a tree here, “The Tree of the Knowledge of Good and Evil.” Don’t eat its fruit.
I know—you want to know why, don’t you?
Well, I have made you as my image. I have given you instincts to enjoy what I enjoy. So in one sense you naturally do what pleases me and simultaneously gives you pleasure too.
But I want you to grow in trusting and loving me just for myself, because I am who I am.
You can only really do that if you are willing to obey me, not because you are wired to, but because you want to show me that you trust and love me.
If you do that you will find that you grow stronger and that your love for me deepens.
Trust me, I know.
That’s why I have put that tree there. I so want you to be blessed that I am commanding you to eat and enjoy the fruit of all these trees. That’s a command! But I have another command. What I want you to do is one simple thing: don’t eat the fruit of that one tree.
I am not asking you to do that because the tree is ugly—actually it is just as attractive as the other trees. I don’t create ugly, ever! You won’t be able to look at the fruit and think, That must taste horrible. It is a fine-looking tree. So it’s simple. Trust me, obey me, and love me because of who I am and because you are enjoying what I have given to you. Trust me, obey me, and you will grow.