Close doesn't count when it comes to obedience

I Sam 15:

When God calls you to do something--no matter what--obey completely. In v. 3, God told Saul to "go and attack Amalek, and utterly destroy all that they have, and do not spare them. But kill both man and woman, infant and nursing child, ox and sheep, camel and donkey." However, in v.9 we see that while Saul and the people had no problem obeying the command to kill the babies, they stopped short at killing "the best of the sheep, the oxen, the falings, the lambs, and all that was good." The telling part comes next: they "were unwilling to utterly destroy them."

When we are unwilling to completely obey God's command, there are consequences. Saul's consequence comes in v. 26: "the Lord has rejected you from being king over Israel." Though he had a reasonable excuse of sparing those animals for sacrifice to the Lord, it was not the sacrifce that the Lord desired--He desired obedience. "Behold, to obey is better than sacrifice" (v.22).

What is God calling me to do? Will I respond with complete obedience?