Why was the Renaissance considered the beginning of the modern age?

The modern age burst into full flower during the late 17th and 18th century period known as the Enlightenment, but the seeds were planted during the Renaissance. The term Renaissance or rebirth refers to the rebirth of interest in Classical Greek and Roman culture that began in the 14th century as the Crusades and other contact with the Arab world brought ancient Greek texts into Western Europe. However, this process of bringing in new texts...

The modern age burst into full flower during the late 17th and 18th century period known as the Enlightenment, but the seeds were planted during the Renaissance. The term Renaissance or rebirth refers to the rebirth of interest in Classical Greek and Roman culture that began in the 14th century as the Crusades and other contact with the Arab world brought ancient Greek texts into Western Europe. However, this process of bringing in new texts and trains of thought challenged the hegemony of Christian theology: in some ways, thinkers such as Aristotle seemed to differ from the Church in their understanding of the universe. As the historian Norman Davies wrote in his book Europe: A History,

The essence of the Renaissance lay ... in the use which was made of classical models to test the authority underlying conventional taste and wisdom.

While the Middle Ages is typically understood as a time dominated by received authority passed down from past ages, the Renaissance, though still relying on the superior knowledge of long ago, began to question that wisdom.

Modernity rejects received authority in favor of empiricism and the rational testing of hypotheses. God, central to the medieval worldview, was pushed out of the modern scientific equation. The Renaissance, by encouraging thinkers to reach beyond the received wisdom of the church, created a spirit of inquiry that led to the modern age.