Answer:
Church was included in the feudal system and had large manors, making it one of the most important institutions in the Middle Ages, but also one of the richest. Pope's authority was so high that he was even able to appoint or overthrew rulers. Additionally, monasteries were the center of education and until the emergence of universities, monks were practically the only educated people.
Step-by-step explanation:
After Papal state was created Pepin III gave it large land that church later on even spread, thus gaining a lot of financial means to have the opportunity to even control political changes in Europe. Pope Gregory VII was even stronger than German emperor at the time. Feudal system was adapted to the needs of church. Church orders in monasteries were the center of education, and they were practically the only one who could read and write for a long period of time.