Mesoamerican pyramids have been around for quite some time now. The first pyramid, La Venta, was dated to have been built around 800 BCE and was built by the first Mesoamerican civilization, the Olmecs. Certain civilizations would hold human and or animal sacrifices in these pyramids. The Temple-Pyramid of the Feathered Serpent had around 200 human and animal sacrifices held inside during holy rituals. These pyramids would be a temple or house for the god/goddess it was built for, or it would be built for a civilization's ruler. It was also common for these pyramids to be a place for citizens to run for shelter and safety from war. 

In conclusion, these pyramids were very important for the civilizations. People now had a place to honor, house, worship and pray, offer items or sacrifices, and take shelter if needed. The pyramids would have history or stories in heirogplyphics or paintings on the walls. Rulers had their own pyramid, where they would be put to rest when they died.