In Saul, God gives Israel the king that it wanted (1 Sam 8-9). But Saul is pious a bit too much according to his own reckoning rather than according to the ways of the LORD. God’s ways are not our ways, but he invites us to make his ways our ways, so we might live from the holiness that comes from God, rather than any other light that we might claim for our own.
God’s command to Saul was clear: Israel was to conquer and destroy the Amalekites and all of their livestock. In his own pious way, Saul carries out the battle and wins the victory, but instead of killing all of the spoil, Saul saves the best of it so that it can be sacrificed to the LORD. That all seems well and good: if the sheep and oxen are to be killed anyway through the sacrifice that Saul intends to offer to the LORD, then what difference does it make whether they are slaughtered immediately, as the LORD had commanded, or whether they are brought to his altar at Gilgal where the people can be present and can share in the sacrifice. To Saul, the latter option seemed better. This choice seems pious enough, but it was disobedient. God did not ask for sacrifice, but, in this case, simple slaughter. Saul does not carry out the command of the LORD, because he think that he knows better than God what would be for God’s greater glory.
We, too, must be careful, lest we let our own piety get in the way of God’s will. As we seek to bring honor to God, we should ask ourselves whether we are actually seeking to do God’s will, or whether we seek to do what we think that God’s will ought to be. If we are doing the latter, then we are actually doing our own will under the pretense of doing God’s will, and that is perhaps the most dangerous temptation of all. If we are so tempted, then let us strive to bear in mind the LORD’s admonition to us, though the prophet Samuel: obedience is better than sacrifice, and submission is better than whatever offering you would make in the stead of the obedience that God asks of you (cf. 1 Sam 15:22).