What was God's message to the people of Israel through Isaiah when they offended him?

Isaiah called upon the rulers and the people of Jerusalem,
whom he referred to as Sodom and Gomorrah to listen to the words of
God/teaching of God. He wondered why they should continue to make (their
multitude of) sacrifices when God had become tired of their burnt offerings and
fats of well-fed beasts and their pretentious appearances in God’s courts have
become an abomination to God who had no need of their offerings and who hated
their new moons, sabbaths, and other religious feasts because they were tainted
with all sorts of immorality. When they spread their hands in prayer, God would
turn away his eyes and He would not listen because they were full of blood.

If, however, they must appease the anger of God, they must wash
themselves clean by removing the evil in their actions. They should learn to do
good, seek justice, stop oppression, defend the fatherless and plead for the
widows. Thereafter, they should respond positively to God’s invitation to
dialogue with him so that even if their sins were scarlet, they would be as
snow; though red like crimson, they would be like wool. If they were willing
and obedient, they wouid eat the good of the land but if they should rebel,
they would be devoured by the sword, 

The ways these issues are still
prevalent in our society today are:  

• Empty sacrifices: People still
  offer empty sacrifices to God, their offerings are not pure,  
• Corrupt
  courts/judiciary: There is no justice, the judges use their position to
  enrich their pockets and victimise the common people  
• Observance of
  rituals: People still cling to the belief that they can appease thier false
  gods through rituals rather than serving the real God according to the
  scripture, 
• Moral uncleaniiness/ immorality: There is moral
  decadence especially among our youth. Their mode of dressing, expression, taste
  and actions show negligence and lack of dedication to the right path,  
• Oppression of the weak/poor: The disparity between the rich and the poor is
  so obvious that the rich become richer while the poor remain their tools. The
  rich become oppressors and fail to assist the poor. 
• Ritual murder: Cases
  of ritual murder occur daily in our society. Killing of innocent people, using
  of private parts of people for rituals are common in our society today,  
• External show of religion rather than inner spirituality: Hypocrisy has
  taken over. The rich donate where they will be praised while they find it
  difficult to propagate the message of God.