It is difficult to know exactly how Saul was in the wrong in 1 Samuel 13:8-15. Some interpreters of the Bible think that this act of “not waiting” on Samuel is the same command that Samuel gave to Saul back in 10:8. Others think that the 10:8 statement occurred several years earlier and this command in chapter 12, though similar, is a separate command. In that case some contend that what Saul transgressed was the command for only priests to offer sacrifices (Num.18:7). Still some say that Saul disobeyed the general command to wait for God’s will to be expressed through His prophet. It is hard to tell.
What is clear, however, is that Saul disobeyed something. He knows it. Samuel knows it. And the author wants us to know it. We know he has disobeyed not only because the text explicitly says so (v.13) but also because he immediately starts making excuses. “The people are leaving, the enemy is growing stronger, I have not performed my religious duty, so let me get it over with.” Saul actually says that he “forced” himself to offer the sacrifice. (v.12)
What Saul is really doing is displaying the false nature of his belief in Yahweh. Notice how he is swayed by circumstances. Notice also how he tries to rely on some religious ritual in order to curry God’s favor (much like the Israelites from chapter 4 who thought of God as a big rabbits foot).
True belief in God does not try to manipulate God to get him to do our bidding. Nor does true belief in God allow one’s self to be shaken by the daunting circumstances that surround. True belief in God says, “I believe you are who you say you are. No giant can stand in my way if you are on my side. Here I am use me for your glory.” I think we might encounter a little shepherd boy pretty soon that talks this way.