During the period 1450-1750, the natural world replaced the religious doctrine where the renaissance cultural promoted the secular values over religion. It is then that the humanists questioned and exposed many assumptions as false and this weakened the theorical underpinnings. Renaissance encouraged people to querry, get knowledge and change which would have not been the case in the middle age. This eventually led to the end of christendom's old idea and the the rise of protestant
one thing that declined it was wars and starvation. rapid growth increase was mainly caused by a decreasing death rate (more rapidly than birth rate), and particularly an increase in average human age,but also no wars and fertility