And said unto them, It is written, My house shall be called the house of prayer; but ye have made it a den of thieves. Mat. 21:13

The Jews had taken something that God had given them and turned it into a place of business. They started worrying more about how much money they could make instead of thinking about their sin. Instead of thinking about how they needed a sacrifice. I think we can make the same mistake. We can just come to church and do it out of duty instead of love for God. I need to have a love for you God and not just go through the motions.