Seems like a lose-lose to me.
Here it goes:
(A)If Jehovah can really read the heart, then he with no doubt would have read the hearts of the perfect Adam and Eve and would have known that they will sin when set up for a (failure) test. Then he would have known that he will punish them and all mankind for many thousands of years, which would case immense suffering, all to prove a point to his archnemesis!
In the real world, an example comes to mind.
Imagine that you are a parent of two children. You love them to death and would do anything for them. Sounds pretty reasonable, right. You also have a gun in your home for protection. One day, as you the children and their infant children are having dinner, a criminal breaks into your home, waves a knife and threatens to kill everyone. You remain calm, manage to pull out the loaded gun and tell him to get out or get shot. The criminal laughs in your face and tells your children that their dad is a sissy and he shouldn't even be pulling out this toy gun. In response, you shoot to death both of your children and all grandchildren to prove to the criminal that the gun is not a toy gun and that he is wrong for calling you a sissy.
Pretty loving, huh?
(B) If Jehovah can't read the heart, then how can anyone in their right mind coldheartedly accept as normal the killing of innocent adults and babies at some cataclysmic event.