God does the heavy lifting.

I will restore the fortunes of Judah and the fortunes of Israel, and rebuild them as they were at first. I will cleanse them from all the guilt of their sin against me, and I will forgive all the guilt of their sin and rebellion against me.

Jeremiah 33:7-8

Three times in these two verses God promises to do the hard work of salvation for His people. They need only believe, accept, and recommit. When it comes down to it, we may repent and we may commit to change, but it is God Who does the real work of transformation in us. He promises His covenant people in this passage that He will restore both Judah and Israel to nation status again. He promises to rebuild their cites and nations after years of destruction, desolation, and exile. Those are physical promises, visible to the world.

God also promises to do the hardest spiritual work in His people. He promises to cleanse them from the guilt of their sin against Him. They would no longer bear the legal guilt of trespasses against God. The Lord, as judge, would waive their guilt and replace it with a verdict of “not guilty”. This is unilaterally God’s work of pardon. They WERE guilty. He would choose to declare them free of that guilt. They did not earn it or in any way prove themselves to be guiltless. God does this cleansing (and it happens now through the blood of Jesus, applied to each sinner who repents and trusts Jesus).

God will forgive all their sin. He will choose to forgive them, which means they were indeed in the wrong, guilty, and deserving of God’s judgment. But forgiveness means that God chooses to no longer hold their guilt against them. God is holy, just, judging sin.... yet He is also merciful and gracious, forgiving when dealing with sin and providing the means through the cross of Christ for all sin to be atoned forever. God does the hard work. He does the heavy lifting when it comes to removing sin’s guilt and offering forgiveness. We are called to accept this by faith and to follow.