The correct answer to this open question is the following.
After reviewing the stories of the Pre-Columbian civilizations of the Olmecs, Teotihuacans, Mayans, Aztecs, and Inca, my conclusion about the most defining characteristic of Pre-Columbian civilization is that they build impressive pyramids and ceremonial centers to worship their gods.
These Mesoamerican cultures had a "vivid" religious belief in which they honored and respect their gods. That is why they built these huge constructions for the time and even their social and family lives were centered on their relationships with the gods. They had gods of war, or rain, of death, or fertility, agriculture, and more.
There are places in México, where you can admire these archeological sites in perfect condition, as is the case of Teotihuacan, Monte Alban, Cholula, Xochicalco, and Tajin.