As I read through Isaiah 1 I'm hearing God's heart.  He's frustrated because His children have turned from an authentic relationship with Him.  They're playing church by offering "treats" but they're not listening to His heart.  He sees them hurting each other and He knows how to stop it but they won't listen to Him.  Their leaders take bribes and they're not listening to Him.  This is what He wants:
"Quit hurting each other. Do what is right. Seek justice! Encourage the oppressed. Defend the fatherless and plead the case of the widow".  He wants us to reason with Him.  He's willing to help us clean up our mess but we need to be willing and obedient.