Saul fails to do all that God has told him to do and is again told that God has rejected him as king. In verse 17 he is told God picked him when he was humble. Now he thinks he can ignore God’s instructions.
Verse 22 tells us God prefers our obedience to our apologies. When we do the wrong thing, we should confess it as it says in 1 John 1:9. God will forgive us, but it would have been better not to have done the wrong thing in the first place.