This diagram reminds us of the spiritual consequences of sin. God is completely sinless and we are not.
The arrows represent all someone might do to try to reconnect with him, but our sin separates us no matter what.
Imagine you had a glass of pure water.
Now imagine someone adds just one drop of poisonous cyanide to the glass. The tiny drop spreads through the whole glass.
In the same way we’d refuse to drink poisoned water, our sin is unacceptable to God. It’s not the amount of sin that matters; any amount is deadly.
God would not be perfectly just if he ignored sin. He also cares too much about his children and his creation to let sin continue to bring death.