God promises us a lot of things, but only if we follow Him and abide by His ways. I always stick to the fact that SIN HINDERS BLESSINGS, so anything rightfully ours is not given to us by the Lord because of our sins and disobedience.
Jeremiah was given a very difficult task by the Lord. Instead of prophesying about God's grace and blessings, Jeremiah prophesied about God's judgment on His people - and heck, nobody believed him! They continued to blind themselves by false prophecies saying that the Lord was good even though they were bad. We should always remember that God is not just some charity or foundation - HE IS A JUST GOD - and He proclaims blessings only to those who deserve them. Likewise, He commands judgment to the unworthy ones.
This is what the LORD Almighty says:
"Do not listen to what the prophets are prophesying to you;
they fill you with false hopes.
They speak visions from their own minds,
not from the mouth of the LORD.
They keep saying to those who despise me,
'The LORD says: You will have peace.'
And to all who follow the stubbornness of their hearts
they say, 'No harm will come to you.'
We shouldn't be believing that something is from God just because it is good. Sometimes, things may look ugly in our eyes, but in God's, they are the best for us. :)