[This is something that a lot of humans, especially humans like L, would comprehend. The fact that Kaworu is no such being comes rushing back at the angel's confused words, and L's fortress crumbles a little. He can be like stone, truly, hard and unforgiving and cold, but when he's confronted by something innocent or childlike, he struggles to maintain the front.]

Sometimes staying away is the best way to care for someone.

[If you're rotten and awful and plan to trespass against God again, especially.]

What he still needs from me can be done at a distance, and... maybe it's better, so. I've made my peace with it already.

[So you see, the prideful part of him implicitly insists, you didn't have to say anything at all.]