It's VERY hard to really do. Easy to SAY, but harder to DO. Or, we truly do "give it over" to Him on our really tough days, but then -- at the first sign of even a SMIDGEN of positive news -- we immediately GRAB IT BACK! It's like playing tug-o'-war with God Himself! (as Drago says in Rocky 3, "You will lose.")
Yeah, it's damned hard. It's also entirely NECESSARY.