There are a number of points that I need to bring up in this chapter which are fairly significant.
1. In the first verses we see that the temple is still standing and the temple was always considered not only the house of God but also the place where God resided. So if God is dwelling there, and it would have been in Jerusalem, then we are safe if we go there, no matter what we do and no matter what we think. Jeremiah says..., well, no, not really. Look at vs.5-7 and we see the conditions that he sets: if you amend your ways and your doings, and if you truly act justly with one another...then I will dwell with you in this place. But we see later on, vs.27ff, that the Israelites will not do this so they were destined to be brought low before God.
2. We see a verse that should be familiar to us. Look at vs.11 and it should sound a lot like Matthew 21:13, go ahead and look it up and see if you agree. We find the words of Jesus as he drives out the money lenders from the temple using eerily similar words that Jeremiah uses to describe the debauchery that was taking place in Jerusalem and in the temple during his time.
3. This is probably the most disturbing part of this entire chapter. It is very clear that there were kings within the reign of God's people who encouraged and participated in human sacrifices. Look at vs.30ff and you see that they "go on building the high places (sacrificial altars)...to burn their sons and their daughters in the fire..." Yeah, that's pretty disturbing and understandably God was pretty angry about it because, "I did not command, nor did it come into mind." While all the other gods in the region were involved in human sacrifice, it had not even entered into the mind of the God of Israel to be involved in such a heinous act.
It is clear that God is not happy with the people at this time.