How was the European church affected during the 1500s?
As you know the historical period about which you ask is known as The Middle Ages or The "Dark" Ages.
One of the conditions of the times that had tremendous effect on the European church in this part of history was the fact that nearly no commoners had any education. Life was consumed with survival so that only the wealthy, the rulers, and the church leaders could even read.
In addition to that, the Bible was not available in the English language. The most common version of scripture was the Latin Vulgate, therefore all religious training of the priests and other teachers in the church was done in Latin.
This meant that the church had total control of the Bible and all religious teaching. During this time, the church developed its hierarchy that almost exactly mirrored the structure of the Roman empire's government.
This was probably the most significant aspect of the development of the church in Europe during this period.