In Chapter 7 Jeremiah condemns religiosity. People were coming into the temple and saying they were worshiping the Lord but they were doing detestable things in God’s house. Are there ways we misuse the church today? Would a modern day Jeremiah condemn our churches for religiosity or for practicing "churchianity" instead of Christianity?

Jeremiah warns about trusting in deceptive words that were worthless.  People were coming to the temple trusting in the religious leaders.  Same thing happens today.  People come to church and trust that everything spoken by the religious leaders is correct, even though they may be hearing deceptive words.

The people in Jeremiah's day thought they could come to the temple, do all manner of evil and yet be protected from any repercussions simply because they thought they had the protection of the temple.  A very convicting verse follows.

Jeremiah 7:11
But I have been watching! declares the Lord. 

Jeremiah 7:22-23
For when I brought your forefathers out of Egypt and spoke to them, I did not just give them commands about burnt offerings and sacrifices, but I gave them this command: Obey me, and I will be your God and you will be my people. Walk in all the ways I command you, that it may go well with you.

God did not give the people these rituals and symbolic practices of burnt offerings and sacrifices in the beginning of the exodus from Egypt. All they had to do was to obey Him and walk in His commands. They had the Angel of His Presence (the pre-incarnate Jesus). It wasn’t until later that God added all the ritualistic regulations, after they had repeatedly disobeyed.

Exodus 33:14
The LORD replied, "My Presence will go with you, and I will give you rest."

He was with them for heaven’s sake! All they had to do was to listen and obey Him.
Oops...He is with us too isn’t He? If we are believers, we have His Presence with us always in the form of the Holy Spirit. So, what’s our problem??? 

Another warning:

Jeremiah 7:27-28 

“When you tell them all this, they will not listen to you; when you call to them, they will not answer.  Therefore say to them, ‘This is the nation that has not obeyed the Lord its God or responded to correction. Truth has perished; it has vanished from their lips.

Sound like the United States today??? 

And again in the following verse, a condemnation.  

Jeremiah 8:6 

 I have listened attentively,  but they do not say what is right. No one repents of his wickedness, saying, “What have I done?”

(See 2 Chronicles 7:14)

Jeremiah 8:7
But my people do not know the requirements of the Lord.

This is because the parents have not taught their children the requirements, nor have the religious leaders.  In fact, according to verse 8, concerning the law of the Lord, the "lying pen of the scribes has handled it falsely." 

Jeremiah again rebukes the spiritual leaders.

Jeremiah 8:11
They dress the wound of my people as though it were not serious. "Peace, peace," they say, when there is no peace.

The “falling away” from godly teaching started early. It was treated as a “scratch” when it was a “dagger” to the heart.

Jeremiah also mentions that the spiritual leaders are not ashamed of their conduct, that they don't even know how to blush.  If a person doesn't even know how to blush, that person has no shame.

(Again, see 2 Chronicles 7:14)

Jeremiah 9:12-13 
What man is wise enough to understand this? Who has been instructed by the Lord and can explain it?  (Theological seminaries alone are poor substitutes for the Holy Spirit who guides us into God's Truth.) Why has the land been ruined and laid waste like a desert that no one can cross? The Lord said, “It is because they have forsaken my law, which I set before them; they have not obeyed me or followed my law. Instead, they have followed the stubbornness of their hearts; they have followed the Baals, as their fathers taught them.

People believe untruths that have been handed down to them. (traditions of men). 

Jeremiah 9:23-24
This is what the LORD says: "Let not the wise man boast of his wisdom or the strong man boast of his strength or the rich man boast of his riches, but let him who boasts boast about this: that he understands and knows me, that I am the LORD, who exercises kindness, justice and righteousness on earth, for in these I delight," declares the LORD.

2 Corinthians 1:12
Now this is our boast: Our conscience testifies that we have conducted ourselves in the world, and especially in our relations with you, in the holiness and sincerity that are from God. We have done so not according to worldly wisdom but according to God's grace.

What a boast…to conduct ourselves in holiness and sincerity because we understand and know the Lord!