Hosea 8

Hosea 8:2 To me they cry out, "O God of Israel, we know you!"
Hosea 8:13 Though they offer sacrifice, immolate flesh and eat it, the Lord is not pleased with them.
When God is fixing to deliver His just judgement, the people see they will lose out and claim to know God. They don't cry out in sorrow for their wrong doings. Just that they know God. They may offer sacrifices as required, but only because they are required. They do this to "save face" and look like they are doing right, all the while still holding onto their sins. In Matthew 7:22-23, Jesus reminds us to be true disciples, that entrance into the kingdom is only for those who do the will of the Father.
"Many will say to me on that day, 'Lord, Lord, did we not prophesy in your name? Did we not drive out demons in your name? Did we not do mighty deeds in your name?' Then I will declare to them solemnly, 'I never knew you. Depart from me, you evildoers.'"

For such a long time, Israel rejected God and followed their own idols. They chose their own leaders and followed those foolishly. They followed in their own wisdom and will get what they deserved. Hosea 8:7 When they sow the wind, they shall reap the whirlwind.
All Israels words to God are just talk. They mean nothing. They claim to know God, but they lack knowledge and wisdom. The Israelites sowed sin for many years, but they will reap judgement in a much shorter period of time. Reaping what you sow is something I try to explain to my children quite often. Especially here lately with the three of them being home together all day, every day. "If you continue to act that way towards your sister, don't be surprised when she no longer wants to play with you." Remember, God always sees and knows. When we continue to sow sin into our lives, it will sprout one day, and we will no longer be able to get away with it. It's like adding the wrong seed to your garden, or not taking the time to pull weeds. If we allow compromise into our lives for the sake of getting what we want faster, it will smother us in the end. Choosing right over wrong is our responsibility, even if it requires time and patience. 

We should examine our own attraction to things in our lives. Have we built up big cities in the sake of protection in our lives, as Judah did against Assyria? Meaning, have we put things in place to "protect ourselves" instead of depending on God? Where are we laying our trust instead of in God? What is wrong with setting our futures up for success? Financial success and nice lives can easily become idols. If God has helped set those things up, that is great, as long as we don't forget how we came about them.